For most writers, the release of their debut novel is cause for celebration.

But for Sydney author Oliver Mol, it marked the beginning of a debilitating, life-changing year. On the day he was due to fly to Melbourne to do publicity for his memoir Lion Attack! in April 2015, the then-27-year-old suffered a migraine so debilitating he almost didn’t make the flight.

“I was working on a short story at the airport when the pain arrived. I remember walking to the bathroom sweating and shaking, the veins in my head sticking out. It felt like I’d been hit in the head with a shovel,” he tells Broadsheet.

Somehow he managed to get through the flight and the event that followed, but the migraine persisted for the better part of a week.

But there was worse to come. Not long after his initial migraine, he was sitting at his computer when he was suddenly struck by pain so strong he fell to the floor and began throwing up. This time the migraine would last a whopping 10 months.

To this day, Mol still struggles to find the right words to explain exactly what happened, but he now understands the trigger was negative press for Lion Attack!.

“Some people called it ‘juvenile’ and ‘a joke’ and I took it to heart,” he says. “But because my work was criticised, I felt I’d been criticised, because I had fused my life with my literature and didn’t understand there was a division.”

Paralysed by pain, he was unable to use a screen, speak on the phone, or even read labels in the supermarket. “I didn’t understand what was happening and no one could tell me [why] and no one could help me,” he says. “It was utterly debilitating and I felt unable to live life anymore.”

Eventually his mum flew him from Sydney to her house in Brisbane, where he slowly and only partially recovered. “I had to train the neural pathways in my brain that said, ‘this is going to equal pain’, because every time I looked at a phone or computer it felt like a sledgehammer slamming into the back of my head. I’d suffered a breakdown and my body was under a lot of stress and wasn’t handling it.”

The next year he still wasn’t back to normal, but he picked up a part-time job ushering at the Sydney Opera House, a job he admits he wasn’t particularly good at because it still hurt to read people’s tickets. Feeling desperate at the thought that his main pursuit – writing – caused him immense pain, he took some painkillers and typed into Seek: “full-time job, no experience, Sydney”, and up popped an ad for a train guard.

Within four months he had the job. It would prove life-changing.

“It was brilliant,” he says. “Suddenly I had a real job, a regular pay cheque and was part of an organisation that told me where to go and what time to have lunch. I was embraced by something larger than myself. I was a train guard for two years, going around and around Sydney until I had worked out how to love myself again.”

His experiences have inspired his debut play, Train Lord.

Mol performs a monologue set to a score by Thomas Gray and Liam Ebbs, with visuals by Kat Chellos that incorporate footage he shot while working on the trains. He gave it a trial run at the Adelaide Fringe in February, receiving rave reviews and The Weekly’s Best Theatre award, despite having no formal acting experience.

Mol is returning this week for a run at the Sydney Fringe Festival, which will be staged live and streamed for a pay-what-you-like fee.

“I hope it becomes hypnotic and you get lost inside it, so the story ceases to become about me and becomes about you. It’s a story of illness and pain but it’s also about healing, about connection. If I do my job correctly I can create a space for people to feel less alone.”

Five years since that first migraine episode, Mol considers himself almost cured. Life is looking up for the 32-year-old, who flies to Georgia following the Sydney Fringe season to begin writing his first work of fiction thanks to an Australia Council grant.

“I’m still not exactly sure what happened but I hope Train Lord [helps others], because if I’d known this story when I was in pain I would have known there was hope.”

Train Lord runs from September 9 to 12 at Newtown’s Old 505 Theatre. It streams online from September 9. For tickets and information visit sydneyfringe.com.