In 1998, Vincent Gallo made a brilliant first feature film called Buffalo 66 , in which a troubled young man, played by Gallo himself, kidnaps a girl (Christina Ricci) and makes her pretend to be his adoring wife on a rare trip home to see his parents (Anjelica Huston and Ben Gazarra). Gallo wrote, produced, directed, cast, styled, scored and edited. He says that he worked 20- to 22-hour days for four solid months. He says that he still hasn't recovered.

One of the scenes, which you'll remember if you saw the film, takes the form of a flashback to the protagonist, Billy Brown, as a boy. To cut a long story short, his pet puppy has peed on the floor, so his father picks it up and strangles it. You think this sounds melodramatic, but Gallo was born in Buffalo in 1962 and chose to premier his film there, hosting a picnic for his extended Italian-American family in the afternoon, at the end of which everyone was limousined to the theatre. Afterwards, one of his cousins, an ex-boxer fabulously named Louis 'Kid' Gallo, was heard to comment that 'If he had made that movie about my parents, I would have punched his lights out.' The movie wasn't autobiographical, but Billy and Vincent had a lot in common. It's tempting to see the premier as a kind of elaborate revenge.

When people refer to him as an actor, he replies that, no, he's not an actor, he's a hustler. He left school and home at 16 and did all the usual stopgap jobs, but also raced motorbikes professionally and, with no formal training, went on to become one of the most successful American painters of the 80s. He was granted his first solo show in Manhattan at the age of 21 and shared the same dealer as Jean-Michel Basquiat, with whom he also played in a band, Gray. Through the 90s, his wired screen presence caught the eye of many independent film makers and he claims to have turned down roles in Reservoir Dogs and Boogie Nights to work with the maverick likes of Abel Ferrara (The Funeral) and Emir Kusturica (Arizona Dream, with Johnny Depp). He is openly contemptuous of the Hollywood milieu and, uniquely among movie people, speaks his mind of his peers; the collaborator who most excited him, he will tell you, was the photographer Richard Avedon, with whom he made the Calvin Klein ad for which he is most widely recognised. Which may be why the screen writer Paul Schrader (Taxi Driver etc) is reported to have told his fellow jury members at the prestigious Sundance independent film festival that he wasn't even prepared to discuss Buffalo 66. 'I don't like Vincent Gallo or his attitude,' he is supposed to have said. Gallo still fumes when the subject is raised. He made a great film, but nobody gave him his prize. Few people can have more enemies in LA than he does.

He lives in the Hollywood Hills anyway, in a striking house designed by the modernist architect John Lautner. He has no agent, no manager, none of the marketing apparatus that usually goes with celebrity, yet is probably the hippest actor in town right now. After Buffalo 66, he was predictably offered further funding for his own films and big money to direct other people's, but instead withdrew to make what turns out to be my favourite record of the year so far, a nakedly beautiful album called When.

He hasn't drunk alcohol or done drugs since he was 14 and admits to being sexually compulsive. He purports to be a right wing Republican. He tells me that his worst times were 1) stepping out of a Parisian nightclub with a girlfriend at the age of 17, saying, 'I feel really happy,' and instantly having a breakdown ('My whole life changed in that one second'), and 2) now. Right now. At least one of these statements may well constitute a lie.

So, having got all that out of the way, it's time to get properly weird. For his next trick, they want him to play Charles Manson.

This may seem a strange place to start in on Vincent Gallo, but trust me, it is the place to start. In 1999, he published a book full of photographs that had been taken of and by him. In his amusing and stylishly written introduction, there's a passage in which he talks in detail about his obsessive adolescent masturbation. Now, any man who tells you that he recognises nothing of what Gallo describes is a liar. But what impressed me was the meticulousness with which he went about it. Displaying great enterprise for a 12-year-old, he planted a collection of porn magazines all over Buffalo, accompanied by little baggies, each containing a scoop of his mother's hand cream. He felt safe, he writes, 'knowing that I could sedate myself all over town'. Yet even this doesn't tell the whole story.

'You know what I would do, because my family didn't have ziplock bags, I would take sandwich bags and I found that by heating the edges of the bag, I could seal it and make, like, little shrink-wrap bags. I spent a lot of time cutting up plastic and forming these little bags. They were good for one jerk-off. I had a fairly compulsive urge about it, so it was fairly serious, the level I went to.'

We've been laughing. Now I notice that he's not anymore.

'Well, you know, it was 15 jerk-offs a day. It's extreme. And as soon as I would come, I would think about it again. And I would do that with food, too. I became harder and more dark about it.'

He speaks with precise diction and a lot of italics. There is just the hint of a New York hipster drawl; his default expression is a mischievous grin. He tells me about the time he almost killed himself by eating too much at his best mate Johnny Ramone's house, where he would go to get a free meal when he was really poor in New York. They called an ambulance and he was revived, but refused to go to hospital. An hour later, he sat up, took a few deep breaths, walked over to the kitchen and devoured a big bowl of cereal with milk.

'I don't know why. Those are two things I don't normally eat. And then I sat back down. That's how I am with work. I'm sort of like a maniac, and I can't get out of it.'

The sexual obsession grew as Gallo's teenage progressed. It became more difficult to maintain his excitement, so he started flashing. Then one day he was picked up by the police and taken home to his hairdresser parents. According to him, this had happened at least six times before, but always in relation to petty crimes like shoplifting or fighting or being caught in a stolen car. The reception he got on this occasion was different.

'My parents were dishonest people. If it was my birthday, I knew my mother took me to the K-Mart and she stole my toy. She'd put it in the shopping cart and we'd walk out. I was raised with that. But then I got caught in this sort of sex crime, that wasn't bringing money to the family, that was socially unacceptable, that showed signs that I was having mental problems, which would reflect on my father. So he either had to blame it on me as some sort of sick, evil mutant, or be responsible for it. Of course, they chose to think of me as naturally being sick from birth. And I knew at the moment of being caught that things would never be the same, that I would never be allowed to be happy, that I would never be allowed to be myself, that my father would finally have a way to put me down and make me believe all the shit that he tried to make me believe, that I never fell for before.'

In his book, he describes a subsequent occasion on which a bra advert appeared on TV and his father turned around and punched him in the face. On another, the old man broke his nose in response to a $55 medical bill for treating a football injury. He had to hide his guitar under the bed, because it was forbidden, and would hear his mother colluding with her clients in the salon as they bad mouthed him. I ask him twice whether all these things are true.

'They're all true. I heard my mother talking badly of me to people who were talking badly of me in her salon. That's probably the thing that I'm most sensitive of in all my friendships and my relationships. I just... I just can't take that. I'm comfortable with enemies, but I can't take it from friends.'

In case you're wondering, this article - and Gallo's life, in a way - is about a question I ask myself often: whether it's better to live with the vivid discomfort of truth, or the numb contentment of self-sedation through drugs, alcohol, delusion, rationalisation, intellectualisation, religion; all those things that take the edge off existence and protect us from having to see ourselves too clearly.

But we're getting ahead of ourselves. The house is perched on Mulholland Drive, where the movie stars live. It's shaped like a concrete and glass rainbow and as you stand on the deck, the view over LA on this bright, warm day is stunning. Gallo has pulled up slightly late in his Jeep and trotted over to shake hands. Today's look is Soho boho; stained white T-shirt, frayed brown slacks and red trainers. His hair is long and straggly and he sports a beard that lends him a passing resemblance to one of his stated boyhood heroes, Leonardo da Vinci. Given that his other boyhood heroes are Chris Squire, the bassist from Yes, and Richard M Nixon, I reckon he looks okay. He's limping badly, because he broke his toe, but doesn't know how.

Imagining that I've been waiting longer than I actually have, he apologises for his tardiness.

'Isn't Polly here?' he asks, opening the door and fussing over his white hound dog.

'Is this Polly?' I say.

'No, this is my dog,' comes the reply. 'She doesn't have a name. It seems kind of weird to give a dog a name.'

I'm still wrestling with this proposition when Polly Harvey, the English diva sine qua non, pads into view. It seems she's staying chez Gallo while preparing for a US tour and I'm trying to imagine them as a workable couple (a match made in the very depths of hell, I decide... though he mumbles something about being just friends) when he asks if I want anything to drink, but she chirps in with 'I expect you might like a cup of tea?'

'What! Tea?' he exclaims, clearly shaken by this sudden outbreak of Britishness in his otherwise staunchly American universe.

Harvey delivers tea and departs, only returning about four hours later, with the words, 'My God, I'd go mad if I had to talk for that long.' Gallo can indeed talk. We settle in the big, open-plan living/kitchen area, around the simple wooden dining table that is Gallo's only piece of furniture. He's acerbic and entertaining, with the fierce intellect of the self-taught. He loves to bate an audience and has one of the driest senses of humour I've ever encountered, even in a New Yorker.

I wonder why he chose to step back from film, at the very moment when he could have cashed in, or done whatever he wanted.

'I didn't want to lose my subjectivity and my objectivity about my work,' he says. 'I'm not looking for a career. And I don't need to be regarded. I'm not Harmony Korine [Gummo] or Paul Anderson [Boogie Nights] or Darren Aronofsky [Pi, Requiem For A Dream], who are already working on their chapter in the history of film books. I have the capacity to do lots of different things. I don't feel that I need to repeat myself like that.'

Besides, he goes on to explain, the economics of a million-dollar offer to direct 'someone else's movie' - which he received - are not what they seem. By the time you've paid tax and spread it over the two years you'll be consumed by it, you're on about $200,000 a year, and he can earn that from an ad or photo campaign, which he'll probably also enjoy more.

'The whole crew in a movie is, in general, lame and out of touch. There's no connection with culture and aesthetic sensibility and art. And the only difference in Europe is that you find more people in the crew who actually like movies there. I mean, do you think Johnny Depp is interesting? He's not. He might be friends with Iggy Pop now, but do you think he bought the first Stooges album? Believe it or not, to me, fashion advertising is more radical and more contemporary and more innovative than independent cinema.

'A Calvin Klein ad is more visually inspiring than nearly every movie poster I've seen in the last 20 years. In fact, everybody on the ad I did was more interesting than anybody that I had worked with in cinema - everybody. By 10 times . I decided then and there that if I ever made a movie, I'd fill the crew with fashion people, which is what I did.'

Is it the ruthless ambition of Hollywood people that he objects to?

'Ambition's OK if it relates to the work. But most Hollywood people's ambitions are to do with what they get from the work. I think I'm good at collaborating, but what I don't do well is collaborate with people who have no real passion about what they do. Film people are suspicious of me. You would think that they'd respond well to my honesty and directness, but on the whole they're threatened by it.'

His love/hate list springs surprises, though. He hates Tim Roth, hated his time with Kiefer Sutherland and the hip director Kusturica, but adored working with Meryl Streep on the cruddy House of the Spirits ('she was the nicest lady I ever met in my life'). He thinks De Niro, with whom he appeared in Goodfellas, should be embarrassed by the monsters he's spawned; on Buffalo 66, Anjelica Huston was a nightmare and Christina Ricci spat, 'You've ruined my life,' when he dyed her hair blond and transformed her from a Hollywood brat into a grown-up actress - though she kept the look for her next film. He gets impatient when people demand to know how he persuaded such big stars to be in his movie, blustering on one previous occasion, 'Anjelica Houston got $300,000 for three days in my film... I paid them you asshole.' For the record, the total budget was $1.5m and he claims that he lost $160,000 of his own money on Buffalo 66, because the people who financed the project knew how much he wanted to do it and cut him a very harsh deal.

So how did he afford this house? He explains that he bought it five years ago, at the lowest point in a low market, and caught the seller in some undisclosed naughtiness, thereby obtaining a further discount (how delightfully Galloesque). According to him, he paid for all of it, and the collection of vintage guitars and recording equipment with which he recorded his album, with 'labour money', working in restaurants, doing plaster work, construction and demolition work. He also bought and sold rare instruments and took his badly paid acting gigs.

I'm back the next morning at about 10am. He's wearing the same clothes and says he's been up all night working on various things. He feeds the dog with, 'She never goes without food, even though I haven't eaten. I don't have a good lifestyle, don't look after myself.'

We spend a long time talking about politics and I enjoy this conversation, partly because an intelligent person who considers that George W Bush might be a good president is a genuine curiosity to me - more so after the horrific events of two weeks ago - and partly because Gallo argues his right wing economic case cogently. Towards the end of the debate, he says: 'If you think of adults as victims, even for a second, you open a door that you really don't want to open. And the worst part about opening that door is that it's the most destructive door to open for the people you're trying to help... I'm aware that, out of context, all this can sound harsh, but I'm not like that. I can't bear to see pain in anyone, or anything, though I do all the time, because I'm not prepared to cut myself off from it. I'm just very conceptual in all ways. If you really believe in principles, if you focus on them more than personalities, it's less dangerous.'

I tell him that I think he's an idealist and that idealism is a means of avoiding the need to think and feel afresh when faced with the chaos of actual people in an actual world. He wants it to be understandable and controllable because he can't face the idea that it's not. That it might be like him. He smiles broadly.

'I told you, I'm an extremist. Even in art, if my work wasn't 50 times more interesting than me and my petty life, it would be useless.'

We move on to the album, which I love. It reminds me by turns of Tim Buckley, Little Jimmy Scott and Frank Sinatra Sings for Only The Lonely. The sound Gallo makes, though, is very much his own: slow and susurrating, with his fragile voice up close in the mix, as though whispering in your ear. Tunes such as 'Honey Bunny' and 'Apple Girl' and the title track, 'When' play like love songs, but sound like laments and I find myself hooked on this tension between love and desperation.

Gallo laughs heartily when I try to explain this. The sentiments are real: he broke up with his last girlfriend, Bethany, six months ago. They'd been together two or three years - the longest relationship he'd ever had. He never had a girlfriend until he was in his thirties.

'Well, in the songs, like the two relationships I've had in my life, my intentions were beautiful, my intentions were hopeful, that I could have the courage to do that, that I could enjoy that. But I mean, I've been shot, stabbed, crashed motorbikes at 100mph and none of those things frightened me, gave me butterflies, regrets, doubts, made me feel bad about myself like those relationships.'

I can't help chuckling. Gallo finally joins the human race.

'Yeah, I know. As I was writing each song, I was thinking, "Oh, this is the sweetest song." But I never realised until I heard it afterwards that it was filled with loss and fear. I haven't really got over this thing. When I did the album I was in tremendous chaos, because I focused too much on the technical part. I recorded for about six hours in the course of this 24 months of making the record. The rest of it was trying to perfect, control these things because my relationship was falling apart. One of the knobs was a slightly different shade of black and I couldn't record until all the knobs matched. That was how I became. I'm a freak now. I'm moving towards an extremely eccentric, withdrawn sort of sick, sick mind.'

All of this is spoken quietly but evenly.

What do you mean sick?

'I'm behaving in ways that are not healthy or productive and are certainly not giving me good feelings. I don't really have intercourse of any kind. So here I am, very much a sexual compulsive.'

You're a movie star. Can't you sedate yourself by having flings with people?

'Never. Never. I'll make out sometimes, try to get a hand job or something really detached. But I can't face the repulsion I get from being with someone who I don't really like.'

Aren't you talking about what I think of as 'the moment of truth', which occurs in men the instant after physical satisfaction, when all the lies and rationalisations that might have led you to this point dissolve in an instant of clarity, when you know if you really want to be here, now, with this person? I don't think women get this. They seem to know before.

'No, women will never understand that. And remember I started having sex when I was 12 years old. I'd fucked six girls and women when I was 12 - and they were horrible experiences, all of them.'

How did you get to do that?

'Cos I was a maniac. The same way I got the rare Rickenbacker bass I showed you, by obsessing every minute of the day. By making myself available to the old man and his 25-year-old wife who picked me up when I was hitchhiking, by being there in the back seat of the Cadillac they were driving, being the one with whom they could live out a fantasy where he gets to watch her giving a young guy a blow job. But as soon as I would come, it would be horrible. And what's happened to me now is that that repulsion is present before I come.'

Most men can lie to themselves up to that point. Hence the bizarre post-coital behaviour which has flummoxed and upset women since the dawn of time.

'That's right. But I can't lie to myself anymore. I'm probably more like a woman in that way. I have to be in love to have intercourse. Which is horrible. I'm worse now than before. And in a city where there's endless opportunity. I'm a physically ugly person.'

What? Half of my women friends asked if I could smuggle you back to Britain for them.

'Really? Maybe because they see me in this other context. I accept that looks is not my best quality and I know it because I know what it was like before I had any public notoriety. I always got the girls I wanted, but that's because I always picked the most broken-down disturbed ones, or they'd choose me. But they were never girls of my fancy. It's been give or take 12 years since I acted out sexually like that. There have been no significant sexual acts with anyone other than my two girlfriends since then and I can't imagine making love to anyone else now.'

That sounds pretty unpleasant. There is a pause.

'Do you drink?'

Yes.

'You see, it's harder if you don't drink because you can't even take the edge off the repulsion. Off your conscientious mind. Off your clarity.'

Why did you decide to forgo the anaesthetic so early in life?

'I was in strife. I was in deep, dark strife and holding on by my fingertips anyway, and I felt that anything that would alter that last grip that I had on life would make me fall. When you take the sedation, you're putting your life on hold, checking out because you don't like this one moment. I can't do that.'

While writing an article on stalking, I once spoke to a psychologist who explained his theory of how the psychopathic mind is formed. He ascribed it to events in a person's childhood and the archetypal childhood he described could have been Gallo's. I point out that he once observed of himself that 'I like manipulating, it's in my nature.' He exhales deeply.

'Well, a lot of people have said that about me... But no one thinks they're crazy. I've had lots of extreme behaviour. But I don't do things without being aware of them. It doesn't mean that I'll always be the best person I can be. But I don't become the worst person I can be without being aware of it. Even if I don't tell the people around me that I'm aware of what I did, I'm always aware of what I did.

'But I had incredible voices during the young period of my life that made it impossible for me to accept any pleasure, any freedom. I'd created a torture chamber for myself. As soon as I moved out of my father's house, where the torture chamber was run by him, I created my own. Paris was the first time it happened and that's the worst time of my life. The second is this period now. Because I thought I'd finally become a real person.'

With Bethany? Do you blame yourself for the failure of that relationship?

'I blame myself for not accepting love. I chose someone who'd play into my most reactive mind, the part of me that's most afraid of being disappointed. And I couldn't forgive that person, realise that I'd chosen that person. Instead I punished her for having shortcomings. It's very odd not to be your best with the person that you like the most.'

A little later, Gallo starts asking me about my kids, with an interest that single people very rarely show. He talks about the problems he's experienced in being consistent with his dog and his horror at getting it wrong sometimes, a feeling that parents know well. Eventually, he says: 'I think the greatest thing you can do as a human being is to be a good parent. That's the most radical impact you can have with your life. The children of good parents, they spread productivity for years to come. And the most evil thing that you can contribute to mankind is destructive parenting.'

Saturday afternoon, a pub in Santa Monica, England has just beaten Germany 5-1 and everything seems a bit unreal. This morning, I met with Gallo again but this time he was limping markedly less than he was the day before. I've also heard some colourful tales from various women whose paths he's crossed back home. Suddenly, I doubt him. Can he be real? I call to ask. He sounds a little hurt at first, but recovers quickly.

'No, man, I don't trust anyone, either. But I hate acting too much and find it too hard work to do it for free. I strapped up my toe differently yesterday so that I could walk better. You can ask Polly. She's seen how swollen it is.'

We discuss the Charles Manson movie some people want him to star in. In fact, he's been toying with the idea of using Manson as the basis for a film for years, but thinks the bio-pic being planned will be awful.

'I mean, to turn him into a character study... it's embarrassing. What am I supposed to do, do his accent and play the "real" Charlie? It's ridiculous. What's the point of it?'

He said he'd do it for a million dollars, because he liked the concept of being 'The Million Dollar Manson'.

Instead, next year is likely to find Gallo slaving on a successor to Buffalo 66, called The Brown Bunny. He's got a thing about the name Brown, he tells me, and, given that I have a grandad named Charlie Brown and a mum who was christened Betty Brown, I decide not to ask why. And do you know what else? In England, I'm informed by reliable sources that he and Polly Harvey are involved in a relationship.

Can he repeat the success he had with that first effort? I don't know. What I do know is that whatever he does is unlikely to be bland. There are times when Vincent Gallo seems like an infantile freak, but others when I think he's the last genuine artist in America. And I'll go back to my sedation now, I think.

His brilliant career

1978: Arrives in Manhattan, aged 16, sleeps in his self-customised blue 66 Chevelle Supersport convertible with his stereo and stolen food.

1978: Spends summer in Paris. Realises that he can 'make it through each day' by drawing. Has what he calls a nervous breakdown. 'France is the best place in the world to have the worst time of your life.'

1978: Returns to New York. Forms band, Gray, with his friend the artist Jean-Michel Basquiat. Makes his first Super 8 film.

1979: Appears in play, Buffala, in Rome. 'I hate plays, never again. Never. Never, never, never.'

1981: Co-manages hip-hop crew New York City Breakers. Is shot in the leg during a gang altercation. Next band, Bohack, releases album, It Took Several Wives - now a collector's item.

1983: First solo art show.

1983: Appears in first feature film, The Way It Is, for which his soundtrack also wins Best Music Award at the Berlin Film Festival.

1984: Gets married. Marriage lasts 10 weeks. 'I can't remember a day with her, but I think she was nice sometimes.'

1987: His friend Jean-Michel Basquiat dies. 'His death was no surprise, but it sure was sad anyway.'

1988: Has a normal day. 'I was 26 years old before I knew what it was like to have an ordinary day. I was in Rome and I immediately came back to New York and went into therapy in the hope of repeating the experience.'

1989: Starts writing the screenplay to Buffalo 66. First book of paintings published.

1990: Vanity Fair runs an article on Gallo the painter. Decides to stop painting. Scores a part in Martin Scorcese's Goodfellas.

1993: Co-stars with Johnny Depp, Faye Dunaway and Winona Ryder in Arizona Dream. Meets Meryl Streep on the set of House of the Spirits. 'I made $30,000, which was enough to support me for a year.'

1994: Stars and steals the show in Palookaville. Makes pocket money selling rare guitars.

1996: Collaborates with Richard Avedon as the face of Calvin Klein for their 'be' campaign. Models for Yohji Yamamoto and Anna Sui, too. Buys Lautner's famous Rainbow House in the Hollywood Hills. Stars in The Funeral with Abel Ferrara - 'He's the only director I wouldn't argue over money with.'

1997: Forms band, Bunny. Assembles cast including Christina Ricci, Anjelica Huston, Ben Gazarra and Mickey Rourke to make Buffalo 66. Films it in one month. Writes for hi-fi magazines.

1998: Buffalo 66 released. The independent cinema hit of the year. Gallo hits magazine covers everywhere. Goodbye Lover, directed by the Brit Roland Joffé (The Killing Fields) and co-starring Patricia Arquette, is released.

1999: With his star riding high in Hollywood, turns back on film. Publishes a book of photography Gallo 1962-999. Starts to record an album, When.

2001: When is released with edgy British underground label Warp. Is lined up for the film role of Charles Manson.