At the heart of every Gerard Burns painting is a pause.

Man, woman and beast are depicted in photographic detail, in the midst of an unfolding narrative, but the scene portrayed is always a moment of stillness.

Meeting the artist himself has a similar feel. By his own admission a workaholic, it is after much planning that we sit down over coffee at his Cumbernauld home, between a client meeting and him "putting in a shift" at his workshop. It was this relentless work ethic which pushed him over the brink, ending his teaching career, and then offered him a way back to sanity.

Burns taught for 12 years, latterly at St Aloysius College in Glasgow, where he became principal teacher of art at 28. "There was no art department really, to speak of, when I arrived, so I just threw myself at it, all my various energies, and we created an amazing art department and, ultimately, created a monster."

When Burns, now 50, joined, there were three students taking Higher art and a handful of Standard grade students; by the time he left there were 65 Higher and 175 Standard grade pupils.

"It was outrageous. It was too much. The department couldn't cope and ultimately my health suffered as a consequence. I had a nervous breakdown. I lost all my hair over a period of four weeks. It was the most bizarre experience of my life. I had really thick, dark blonde hair and I noticed that it was coming away. Within four weeks I was bald as a coot. The writing was on the wall by that time."

It was the October week and Burns and his family went to Cyprus. He never returned to teaching. "The great thing, in retrospect, was because this was so visual, and it hit me in my weak spot – my vanity – I couldn't hide it."

A small settlement bought him time and eased the transition from teaching to painting full-time. "People will say that it was really brave and I suppose in retrospect it was. A braver thing to have done would probably have been to try and go back to teaching, but I knew it was over, there was no question."

"That whole experience of going into the unknown was probably the most frightening point, without a doubt. It was a position I've never been in my life before and hopefully never will again."

It was a particularly worrying time for his wife Ellen, who was working part-time as a midwife and had to go full-time to support the family. "I was a principal teacher. We had a good life. We had three wee kids and for her, as much as for me, the rug was pulled out from under her feet."

However, released from his day job, Burns was prolific. "I had all this time and energy and made hundreds of paintings. Part of my problem is that I work. I didn't ever sit around. I came back from Cyprus and I launched into it. The only way I could stay sane was to begin to be a full-time artist the day I stopped teaching.

"No matter how much I was doubtful about having made the right decision financially, I knew if I was ever going to be good at anything, it was painting."

For Burns, art has been part of his life for as long he can remember. "The problem probably was that I didn't have any role models particularly. There was never anybody you could say that this could be real, that I could do this as a job."

Natural landscapes are prominent in his work and his love of the outdoors was part of the reason he opted for civil engineering at Strathclyde university. Art, after all, wasn't a job. "I remember going to the careers office and there was no way I was going to be going to art school. It was a case of well, you'll go and do something serious. I had this weird notion that I wanted a job outdoors, so the careers people suggested engineering."

It quickly became apparent it was not for him. "It was a monumental disaster for me. What I discovered was that there were different types of brains. Until that point I could kind of do everything, more or less, as well as everybody else. Then I went to do engineering and I just thought: 'I am the dunce of the class here. I absolutely don't get this.'"

He pulled a portfolio together and got accepted into Glasgow School of Art, where he studied painting, but becoming an artist seemed like fantasy. "You just enjoyed it for what it was worth and then you taught if you wanted to keep your art going. There was a couple of people, Ken Currie, Steven Campbell, who did go on but they seemed to operate on another level of self-awareness. There was no way that that filtered back to us in terms of 'you could be doing this'.

Instead, he pursued music. His band Valerie and the Week of Wonders signed a record deal with A&N but never made the big time. "It was a shame, it was politics within the record company, but that got me out of art school and I was about two years with the band, and then I continued on with my music with other people."

A subsequent band, Heaven Sent, supported Simple Minds. They were on the periphery of bands like Del Amitri, the Bluebells and the McLuskeys, and Burns says: "Not for one nano-second do I regret it, but I don't remember thinking, 'Wow, this is the life', because I really wanted to be successful at it. I believed that the band was good enough and we got tantalisingly close at points, but we never got over that threshold."

Having made the tough call that fame and fortune did not beckon, he trained as a teacher. "I got married and I just got tired of being skint. But of course, the truth was that from the minute I stepped into a classroom I absolutely loved it. Arguably, it was the making of me."

With his love of art reignited by teaching, he went on to become one of Scotland's leading artists. Best known for his large figurative oil paintings, his themes are often based on stories from classical mythology and Christianity. Indeed, matters spiritual are never far from his mind. "Absolutely, I would say it [spirituality] is how I define myself. I was brought up Catholic but less and less I find myself attracted to the institutional side of religion but more and more I am utterly convinced that we are spiritual beings. Christ himself is a conundrum which I wrestle with daily and these paintings, I suppose, are part of that process."

Arguably his most high-profile painting is A New Journey, which appeared on the First Minister's Christmas Card in 2009 and featured his niece Hannah McQuillan holding a saltire. "I thought; 'This is perfect: it's Scottish, it's a winter scene, it ties in with what I do'.

He can still recall unveiling it to the First Minister. "Salmond got down on his hunkers and really stared at it. He was saying, 'What do we call it?' I didn't have a name for it and said he could call it what he liked.

"It was portrayed as if he had manufactured the situation, [as if] he had asked me to do something. He didn't. He was presented with it, but he was astute enough to think: 'Fantastic'. From my point of view it was fantastic publicity."

Burns was invited to Banff for the official launch of the card. He almost didn't go. "I wasn't very well. I suffer from asthma and for two pins I was for cancelling."

"Moments before the launch the First Minister took me aside and said: 'Just so you are aware, there might be a bit of a stushie surrounding the Christmas card. There has been a question raised in the parliament about the appropriateness.'

"I hadn't foreseen that reaction. That was a bit of luck in my view. I've always really tried hard to remain slightly distant from the actual party politics of it. I am an SNP supporter now, but when this all started, I don't think I was. I was slightly ambivalent."

Clearly, Burns is relaxed at the epicentre of controversy. Which is perhaps why he is fascinated by the subject of his latest painting – Celtic manager Neil Lennon. Painted from a photograph, it shows Lennon against a wall of graffiti – which Burns often uses to signify moral decay. The slogans are sectarian.

"It's scary stuff but I actually am quite drawn to, quite fascinated by, people who provoke or inspire that level of emotion. To live with it, to get up with that in the morning, you must have an unbelievable self confidence to shoulder that responsibility and know that there is that level of hatred and still put yourself up there. You must have to be extra special."

He describes his approach as "artisan": while the inspiration can strike, it's often just long hours of graft. "There's nothing particularly glamorous about it – you spend your life in scabby paint-splattered clothes."

He is now keen to raise his profile in the US and hopes work hanging in Mary Queen of Scots, a Manhattan bar owned by friends, will help. He is making a first foray into sculpture, something he has been desperate to do for some time, and other projects vie for his time. Speaking of which, it's time to get back to work. He drains his coffee and heads to the workshop to get cracking – muse or no muse.

Gerard M burns

LIFE AND LOVES

Career high?

Selling a painting to Ewan McGregor (pictured) and meeting him at his home in London. It was the premiere of Big Fish and he said: "Why don't you come along?" My wife Ellen flew down that afternoon and we did the red carpet.

Career low?

It has to be leaving St Aloysius.

Favourite holiday destination

Cadiz. We bought a house there eight years ago. I'm over once every six weeks and I'm there for a big chunk of time in the summer.

Favourite film?

Blade Runner.

Last book read?

I'm ploughing through audio books in the studio. The Grapes of Wrath by John Steinbeck is wonderful.

Worst personality trait?

Obsessive compulsive. I can't let something go once I've got it in my head.

Best personality trait?

I'd like to think I'm quite generous.

Biggest influence?

My father Joseph.