Wilko Johnson is one of the world's most famous guitarists you've never heard of. His idiosyncratic choppy playing style is credited with influencing a legion of punk guitarists. To a generation born long after punk, Wilko might be better remembered as the executioner in the TV series Game of Thrones. TV stardom or a life of rock'n'roll seems far away as he sits cross-legged on his sofa at home in Westcliff-on-Sea, Essex. Now 66, Johnson grew up a mere stone's throw away, on Canvey Island in the Thames estuary: a flat, densely populated land mass surrounded by creeks and marshland, famously dominated by a colossal oil refinery, a rich source of inspiration for songs he wrote while guitarist in Canvey's cult heroes Dr Feelgood.

He seems well and in a good mood, relaxed. Seems, because last year he was diagnosed with terminal pancreatic cancer. "I've never felt more alive," he says. "It's one of the most intense years I've had. The things that used to matter – bills, worrying about the future, thinking I could change the past – don't matter to me any more. They're nothing to me now. I'm embracing the present." It's easy to believe him, too. He says this with a smile, casting a glance at his garden. "I mean, look at that tree out there. I can sit here looking at it all day. It's a beautiful thing that makes me tingle. I can feel everything bursting through me." Everything? "Yeah, you know... life, the real stuff."

Such philosophical honesty is refreshing, and it's no surprise to Wilko that the media has renewed its interest in him. "Oh, there's been TV people and broadsheets wanting to talk to me almost every day now. It must have something to do with that fantasy everybody has: what would I do if the doctor said to me I've only got a few months to live? So when that did happen to me, my reaction was not what I would have thought. I just got on this fantastic high, and I feel intensely alive. What you have to do is you just have to live for the minute you're in."

Download the new Independent Premium app Sharing the full story, not just the headlines

It is a take on life that's served him well. In the mid-1970s, when Dr Feelgood burst on to the world stage, displaying their visceral, R'n'B-driven angst, it was Wilko who seemed most conscious of the ride. "I always knew what we had was good. Even when we were kids, playing outside the pubs on Canvey, it felt good. It happened quickly. It was Lee [Brilleaux] who had it; it was all because of him. He crackled with electricity and I fed from him. Lee was the wellspring and I just went with it, experiencing every minute. I always knew it would end, too. Everything went right, until everything went wrong."

Wilko left in 1977 when things turned bitter. Some say he was pushed. "I think it was Lee and me, we just didn't get on in the end. I mean, if we walked into the same room, one of us would walk out – it got that bad. The animosity we felt for each other was something else. For the life of me I don't know why. I mean, we were always different. But we always admired each other. I regret we never expressed that to each other – our admiration of each other." It's almost as if he feels things might have turned out differently. "Maybe, yes."

The differences Wilko refers to are literature, poetry and art. Before Dr Feelgood, Wilko was an English teacher who'd graduated from Newcastle University with a degree, specialising in medieval literature and the Icelandic sagas. Before that he'd been a political activist who'd travelled the hippie trail through Afghanistan and India. He wasn't your average working-class Canvey Island lad. His paintings hang on the wall above him, surreal things that seem to echo the literature he was reading at the time. "I played in bands before university, but when I went up to Newcastle I couldn't find a band, so I quit playing. I started writing poetry and painting. The sagas I was reading, they blew my mind, just so poetic and brutal. The painting came naturally. I continued painting after the travelling, especially when I got back to Canvey. I took it seriously, too. Working on my technique, you know. And then the band just seemed to happen by accident and I stopped, but it never left me. Ironically, the last piece of artwork I did was the Dr Feelgood logo – my most famous piece."

He speaks in loops, repetitions and tangents. His voice carries the scars of a life on the road in a rock'n'roll band that you don't hear in younger musicians these days. His living room is packed with electrical recording equipment, radios, dials and spools. It's as if he is sitting in his own control room, tuning into the outside world around him, listening to snippets of life before the signal fades, or he moves on to something more interesting along the dial.

"The great literature I've read has never left me. It's always there, reverberating through my head. I love Shakespeare. William Blake, too. William Burroughs has always felt like a friend. I can't think of Dr Feelgood without thinking of Dr Benway in Burroughs's Naked Lunch. I see him as Dr Feelgood." Wilko is laughing as he recounts his love of Burroughs. It's as if Wilko knows something, too. Something the rest of us don't. "I look at people now, walking to and fro through the city, along the streets, and I can't help but think: you don't know. You don't know what it means to be alive. And I guess they won't know until their doctor sits them down with the dreaded news."

Wilko's still smiling. "I've never been a pub man, but lately I've started going to the Railway in Southend. I go for the music mostly, but I also like it in the day, when it's quiet. I like to sit in there and think. I like to sit there and think of all the good things."

Curriculum vitae

1947 Born John Peter Wilkinson, Canvey Island, Essex.

1965 As a teen he would play his first Fender Telecaster for half an hour every Saturday while he saved up the £90 to buy it.

1968 Marries Irene Knight. She goes on to become his booking manager. The couple have two children.

1970 Graduates from Newcastle University with a degree in English language and literature, becoming one of the UK's few speakers of Old Icelandic.

1971 He meets future Dr Feelgood bandmate Lee Brilleaux, following a brief encounter as teenagers, and joins his band Dr Feelgood. They reach No 1 in 1976 with their live album Stupidity.

1977 Wilko leaves Dr Feelgood and forms his own group, the Solid Senders.

1980 Joins Ian Dury's Blockheads and co-writes several songs with Dury.

1985 Forms the Wilko Johnson Band. They have been touring ever since.

2004 Irene Knight dies of cancer.

2009 Julien Temple releases Oil City Confidential, an acclaimed documentary about Dr Feelgood.

2011 Appears in Game of Thrones.

2013 Diagnosed with terminal cancer in January.