Twenty-five years of substance abuse and a slide from global star to a homeless junkie had to end in one of two ways.
Get clean or die.
So it is apt and fitting that he chose his home town as the place to remove himself from the alluring drug pressures he experienced in London for so many years.
In his smart, spotless and deceptively spacious three-bedroomed home in River he seems at peace with himself.
"Now I'm in Dover I am Nick, not Topper, because that's how people remember me," says the former Dover Grammar schoolboy.
Indeed, as he walks his dog, a Staffordshire bull terrier, Yousah, everyone seems to know him and greet him kindly.
His mother Margaret and father Philip, both retired teachers, live nearby and have been his enduring rock of unconditional love through some very trying times.
At home, apart from The Clash CDs in his surprisingly small collection, there are no visible references to the band - but one or two to his daily struggle to stay clean.
Decades of drug-taking - at least 17 years as a heroin addict - don't appear to have taken too bad a toll. He is neatly turned out, fresh-faced, with a healthy glow which belies his 49 years.
"Sickening, isn't it?" he says with a boyish grin. "If anybody in The Clash should be dead, it should be me."
Nick, who joined The Clash in 1977, was anointed 'Topper' by the band, and was first heard on the Give 'Em Enough Rope album which cemented their British punk following.
But it was the sublime London Calling double LP which helped them break the United States and propelled The Clash into superstardom.
Nick charts his lapse into drug abuse by album. He was clean during Give 'Em Enough Rope and London Calling, going downhill making Sandinista - and out the door by Combat Rock, to which he contributed the worldwide smash Rock the Casbah.
The Clash, like most bands on the road in the late 1970s and early 80s, were steeped in a culture of booze, amphetamines and cocaine. Constant touring meant breaks at home were rare and often short-lived, but they were to be the catalyst in his downfall.
"I loved playing live, touring and life on the road. Coke and booze were the done thing and I did it like everyone else.
"When we came home we were given a month or so and told to 'go and amuse yourselves' before we took off again. During that downtime I starting using heroin, sniffing it.
"It was a slow process. But by the time we were recording Sandinista I knew I was in a jam because I was having to score regularly.
"Once when we came back off tour we had two months to kill, and when we had to go back on the road then I realised I had a habit."
Getting drugs-busted in 1981 at Heathrow airport, being constantly late or failing to show up began to rankle with other band members.
Frontman Joe Strummer decided not to take him on tour, bringing back drummer from the first album Terry Chimes as a 'temporary' replacement.
"I didn't have a lot of choice in the matter. It must have been so annoying for them because I was always messing it up. I must have been given a few warnings before I was replaced. I suppose if I'd got myself sorted out by the time they got back that I'd have been back in.
"Then there was an interview in the States saying that I had been sacked. I went from being Topper Headon, drummer with the - The Clash, taking a break for 'nervous exhaustion' to Topper Headon, sacked for being a heroin addict." Strummer did not take the decision lightly and kept Nick's photo in his wallet for years after his 1982 departure. "Once I was out of the band, it was the beginning of the end - I never injected heroin until I was out of the group. I had nothing to live for and, being stupid, I stuck needles in myself."
Nicholas Bowen Headon turned hedonist and hurtled on a spiral so downward, so fast and so long that it didn't stop until the millennium dawned. As a measure of just how far he fell in the intervening years, Nick was jailed, went bankrupt, became homeless and busked on the London Underground. He was in and out of rehab trying to conquer his all-consuming addiction.
"At first it was drugs and squandering money on fast cars and stuff. I did my best to spend all I had, and in the end I went bankrupt."
He can raise a smile for some of the things he did in pursuit of heroin.
"I was London's most useless minicab driver. Before tough regulations came in, all you had to do was pay a few quid and you could work. It was the preferred job of recently-released prisoners.
"I'd get a fare, ask them where they wanted to go and hand them an A-Z." Desperate for easy cash, he and another musician busked the London underground stations, Nick on the bongos and his partner on sax.
"People would be coming down the escalator nudging each other saying, "Isn't that Topper Headon from The Clash?" It was terrible, humiliating- but I didn't care. I lived for drugs.
"Once I had got to £25 I'd pack it in because I would go and Score drugs. My partner wasn't too impressed with that. "As an addict, I'd wake up in the morning and think, 'Shit, I've got to do this all over again today...'"
Even a ten-month spell inside Stanford '11 prison - he was jailed in late 1987 - on the Isle of Sheppey for supplying drugs to local man, Barry Waller, who subseuently died of an overdose, did not bring him to his senses. The court did acknowledge drugs were not the sole contributor to Mr. Waller's death.
Nick also spent two months in a hostel for the homeless - the St Mungo's chariy opposite Paddington Green police staion - as he plumbed new depths in his life. "It's not been an easy road and certainly not one I would recommend to anyone.
With drugs, I would take whatever I could take - that's what addicts do. You don't buy 40 quid's worth and make it for a couple of days. You take the lot.
"I was desperate to stop and get out of the lifestyle - but I couldn't see any way. So many of my friends have died. There a lot of heroin addicts in Dover and they need help, but they don't know how. It's awash with it around Pencester way."
The turning point came five years ago when he had a car crash, ruptured his spleen, crushed his ribs, punctured a lung and suffered a serious head injury.
Haggard, desperately weak and weighing just eight stones, he retreated to his hometown. "I have to be away from the temptations of London. I like Dover and the people - it's home. There's no point in looking back or looking too far far into the future. My mum and dad have been totally supportive over the years and I owe them a lot. It's up to me now to be the best son I can for them."
To celebrate the 25th anniversary of London Calling, a special. two CD and set is being released on September.