For the first few minutes I'm not even sure this interview should be taking place at all. The greeting is an awkward shuffle of hunched shoulders and downcast eyes; he can't look at me, and I can't hear him. His gaze averted, hands stuffed into pockets, he mumbles in haltingly reluctant whispers, as if words can cause him physical pain. The man should be talking to a doctor, I worry, not a nosy journalist. We try some small talk, but it's almost impossible to make out what he's saying – until I ask what he prefers to be called. "Adam," he says firmly, glancing up for the first time. "Adam Ant." Does anyone ever call him Stuart? "Me mum," he half grins. And then gradually, inch by inch, he starts to relax.

It is still quite a stretch to believe this can be the same man whose fearless, white-striped face stared down from the bedroom wall of pretty much every teenage girl I knew back in the early 80s. Fifteen hit singles – among them Prince Charming and Stand and Deliver – in just three years, and lavishly baroque videos, made Ant one of the decade's first pop superstars, inspiring Antmania in a generation of hysterical fans and selling more than 16m albums, before the singer quit in 1986, to become an actor in the United States.

Over the years since then he has acted in some respectable if unmemorable TV shows and movies, made a couple of moderately successful albums, and toured small venues across Europe and the US. He married briefly, had a daughter, divorced and moved back to London. But he has also been diagnosed with bipolar disorder, hospitalised repeatedly, medicated, sectioned and convicted of affray. He last made the national headlines in 2003, when he was found by police, tearful and half naked, curled up in the basement of his local cafe, having just attacked his neighbour's flat.

Adam Ant performs Stand and Deliver in the Guardian's studios in October 2011. guardian.co.uk

But next month the singer will take to the stage again, performing live at the Proud Gallery in Camden, London, to launch a photographic retrospective of his career. As with many 80s pop icons, it is easy to recall his flamboyant camp as faintly comical, but the exhibition is a startling reminder of his commitment to an aesthetic that was fanatically detailed, highly imaginative and heavily influenced by the sensibility of punk. Ant's relationship with his younger self bears no trace of ironic nostalgia, and he still gets annoyed when anyone muddles him up with the early 80s new romantic scene.

"Cos new romantic was nothing to do with Adam and the Ants. The Ants was a punk band, or a post-punk band if anything, and so historically it's inaccurate. New romantic was basically, in my mind, clubbers with too much makeup on with stupid clothes. I never set foot in any of their clubs, so I find it quite distressing to be nobbled into new romantic, cos it was just a load of guys who looked like they'd had a row with their girlfriends' makeup. There was nothing tough about it, nothing dangerous about it, it was soft electro stuff and it just looked a bit wet. And I didn't like being associated with it."

A man of 58 who still cares this much should probably come across as faintly ridiculous, but the intense seriousness with which Ant deconstructs these arcane distinctions conveys an impression of almost heartbreaking vulnerability. He is also, though, surprisingly pragmatic about the choice between art and commercial success. The first Adam and the Ants album, released in 1979, was too "self-indulgent" to sell well, and he admits: "I wanted money. I just wanted to be – well, I'm quite a competitive person, I want to win. When you work as hard as you can and as much as you can to make your first album, and you don't make any money, then you change things."

Adam Ant with fellow vocalist Jordan in the early incarnation of Adam and the Ants, the Music Machine, London, 1977. Photograph: Ray Stevenson/Rex Features

So Ant hired Malcolm McLaren to manage the band, but it didn't quite go to plan, because McLaren promptly poached most of its members and formed a new group called Bow Wow Wow. "I was none too pleased. But I also realised that Malcolm was pretty much telling the truth. He said: 'What do you want? Do you want to make records that everybody hears – be as popular as cornflakes – or do you want to be a cult artist?' I said: 'I definitely want to make hit records.' And he said: 'You're going the wrong way about it.'"

Ant found new band members, made a second album in 1980, and struck gold. "I played over 100 clubs before I played Top of the Pops, and in three minutes on Top of the Pops my entire life changed." Given his formative attachment to punk – he can still recall the moment he first saw the Sex Pistols perform live in 1975, and thought, "Now I know what I want to do" – did he feel at all squeamish about appearing on the BBC show? "Well, I'd watched Roxy [Music] on it, and [Marc] Bolan, and the Stones, so I thought if it's good enough for them, why shouldn't it be good enough for you?"

He became a star overnight – and it was everything he had dreamed of. "I loved being in a band," he says simply. "But I was working hard, and I didn't drink, smoke or take drugs at all – I'd set myself almost a Spartan social life." He even drew up a contract prohibiting his band mates from taking drugs. Would he say he was quite controlling? "Well, it was my band. And I wouldn't put up with drugs. And that's what finished it; drugs began to creep in, and I wasn't having it."

Before long he had sacked most of the band, made a successful solo album, and continued to work flat out. His prodigious capacity for work was equalled only by Olympian promiscuity; he has always said his only form of recreation was sex, and when I ask how many women he thinks he slept with, the speed of his reply – "No idea" – suggests a man who has a pretty good idea, but is never going to say. "I just think it sounds like bragging. It would be naive of me to deny there was a lot of girls involved, but for me to give it a number – that's disrespectful."

Was he happy? "I was intensely busy. The touring was crazy, it was a lot of work. But I enjoyed it." Did he have everything he wanted? "I wanted to make good records. But my problem is I've got a low boredom threshold, so I wanted it to look and sound different with each album, which is really tantamount to suicide, cos people lose it, they lose it – they say: 'I like that, and that's not this.' Like with AC/DC or Led Zeppelin, they just stick with that. It's pretty much the same thing. But I didn't want to."

An embarrassingly flat Live Aid performance in 1985 confirmed his departure from the Top 10 for good, but his other problem was to prove much more serious. "The trouble was, I forgot to take any time off. At the end of the day it catches up with you. And it caught up with me in a big way."

Born Stuart Goddard in 1954, into impoverished post-war inner London, he was the only child of a violently unhappy working-class couple who divorced when he was seven. But by then he had already begun suffering from hallucinations. "Yeah, nighthorses – horrible. It was just like a very hallucinogenic kind of feeling; I was awake but it was terrifying. Obviously you don't need a shrink to work out what caused that kind of stuff. If your parents are very unhappy" – and suddenly his voice changes, no longer sanguine and philosophical, but angry and hard – "and beating the fuck out of each other every night, well, you know that's going to happen." The tone of quiet resignation is back as he adds, almost to himself: "Yeah, it was a bad do."

After school he enrolled at art college in north London, married a girl on his course and moved in with her parents. Still only 21, it wasn't long before he began to feel suffocated, trapped in a life that was never going to work – and so he swallowed the contents of his mother-in-law's medicine cabinet. "I think it wasn't a serious attempt to kill myself, but it was serious enough for me to draw attention to the fact that I was very unhappy in that situation, and I wasn't telling people how unhappy I was in that situation."

Discharged from hospital, he changed his name to Adam Ant, formed the band, and success soon spelt the end of his marriage. The long list of subsequent girlfriends included Amanda Donohoe, Jamie Lee Curtis, Heather Graham and Carole Caplin, but it was a woman he had never even met who triggered his second breakdown. Besieged by a mentally unstable stalker in the US, who poisoned his fish-pond, tried to kill his dog and would stand naked outside his house shouting obscenities and threatening to castrate him, in 1994 Ant checked himself into a psychiatric hospital, in a state of hypomania, and was diagnosed with bipolar disorder.

Adam Ant in a publicity shot for the single Stand and Deliver, 1981. Photograph: Allan Ballard/Scopefeatures.com

He remarried in 1997, to a PR for Vivienne Westwood, and a year later their daughter was born. "I became a man. Before that I was a little boy. My daughter's the greatest thing that's happened to me in my life and she turned me into a more responsible man, as opposed to just someone who's a perpetual teenager, thinking you're a man when you're not. I took five years off to be with her, and I enjoyed being her dad, and I had enough money to do it, so I was able to not work for five years and look after my daughter."

But by 2002 the marriage was over, the money had run out, and the pressure was reaching danger level again. He had been hospitalised the previous year but had stopped taking his antidepressants, and after decades of abstinence had begun drinking again. Following an argument with a local man, Ant marched into a Camden pub intending to confront him, but was laughed at; he stormed out, returned with a second world war pistol, hurled a car alternator through the pub window, threatened to shoot, and then fled, before being arrested by armed police, bailed and promptly sectioned in a secure psychiatric ward.

He recalls the drama now with a mixture of remorse and righteous indignation. "This was someone that had this delusion that I was doing something with his wife, and I wasn't. So it all got crazy. I basically took the law into my own hands, which was the biggest mistake of my life, I'd never broken the law before, I'd never even had a driving ticket. So you do the wrong thing. Like I say, it was the biggest mistake of my life."

At the Old Bailey he pleaded not guilty on grounds of insanity, but later admitted a lesser charge of affray, and escaped a custodial sentence. But the following year he attacked his neighbour's flat, was sectioned again, and spent six months in a psychiatric hospital.

"I was in a very bad state of mind. But you don't walk into a doctor's surgery and say I'm nuts – and if you do, they just fill you with antidepressants which just turn you into a Tellytubby. Antidepressants are very good, but it's a clinical cosh, really. Sometimes you have to be knocked out, just to stop; when you're in that state all you want to do is just sleep, and rest your body and your brain. But being on antidepressants, if you're not careful you can just be sitting on the couch looking at daytime TV, eating and doing nothing at all." Which is pretty much what he did for the next four years. "And I didn't enjoy it."

Ant talks quite openly about his mental illness, but seems unresolved about medication; he knows he's not well, but the drugs that stabilise his mind also anaesthetise his creativity, and if that is the price he must pay for sanity, he's not sure if it is worth it. When I ask if he is taking medication at the moment, he pauses before answering. "No. But I can if I want to, if I have the warning signs, and I know the warning signs, I can go and get them."

What would be a familiar warning sign? "Well, the trouble is, when you look at the list: sexual promiscuity, spending loads of money, flamboyant behaviour – well, that describes every rock'n'roll star I can think of. That comes with my profession. So it's very difficult to know."

I hadn't expected Ant to still think of himself as a rock'n'roll star. Forged more than 30 years ago, in the heat of Top of the Pops camera lights, this self-image should by now be preposterous – and yet, in his case it seems somehow heroic. He lives alone with his two dogs, close to his daughter, runs his own record label, and talks about his young acts with tenderly paternal protectiveness. One of them is Georgina Baillie, of Sachsgate infamy; "I think it was pretty cowardly, what went on there," he offers with gallant disdain. "Quite shocking, really."

There is an innocence – an almost monastic purity – about Ant's enduring devotion to pop; after coming off antidepressants a few years ago, he began performing live again, playing modest venues, often unannounced, and later this year he will release a new album. I find myself hoping his audiences are respectful, and kind.

Though still beautiful, he has to wear hats and bandanas to disguise the fact that he is now bald. He was always very conscious of his own beauty – "I think to be a pop star you need sex, subversion, style and humour" – and the hair loss seems gratuitously cruel. "Yeah," he admits with quiet sadness. "It was pretty awful.

"But – I dunno – you've just got to do what you can. It's part of the job, really. Just gotta get up, have a shave, and get on with it, really."

Adam Ant will be performing at Proud Camden in London NW1 on Tuesday 6 March to launch an exhibition of portraits, Adam Ant: Dandy in the Underworld, at the gallery from 7 March - 29 April. All proceeds from the event will go to DebRA, a charity working on behalf of individuals and families affected by Epidermolysis. For tickets and further info: visit www.proudcamden.com

This article was amended on 19 February 2012 to give Stuart Goddard's correct surname. The original article used Hubbard. It was amended on 20 February 2012 to correct the spelling of Marc Bolan. It previously stated Mark.