Nathaniel Hall had already toured his autobiographical show about living with HIV when he was cast in It's A Sin.

Diagnosed two weeks before his 17th birthday - after his first sexual experience - he shared his story with "screen writing hero" Russell T Davies while he was writing the Channel 4 drama.

And Hall ended up playing a boyfriend of Olly Alexander's character Ritchie Tozer in the series, which followed a group of friends living through the crisis in the early 80s.

He says its success felt like a cultural moment: "It was part of our history that hasn't been explored on mainstream telly. There have been narratives in soap and dramas, but we'd never had a drama that looked at the effect of the Aids crisis on the gay community as it hit. Even an award winning writer like Russell struggled to get it commissioned. But it was about universal things like love and loss, and showed that you can create a piece of LGBT drama that's not denying the realities, or hetero washing, and connect with audiences."

Hall, whose show First Time runs at The Pleasance during LGBT History Month, says they knew it was important during filming, but had no idea of the impact it would have.

"For there to be such a heartfelt outpouring by mainstream society was incredible. People messaged to say thank you. Those who had lost lovers and friends had felt their stories had been forgotten, and a new generation said 'nobody told us about that in school'. So much LGBT history has been erased, we have to discover it for ourselves."

For years Hall kept his status secret from all but close friends.

"I lived in secrecy for 15 years and that shame and internalised stigma had got in the way of my life in a bad way. Because of the trauma I was carrying, I was in a toxic relationship, leaning on drink and drugs to get me through the week, and had a breakdown. Making the show was about ridding myself of that secrecy. I had to get it out and as an actor that meant publicly."

That decision "forced his hand" to finally tell his family, who were "caring and understanding".

"I had struggled to tell them for so long. I posted a letter and they came to see the show which was very difficult for them. When you carry a secret with a lot of shame, your fear builds about what might happen and is often unfounded. I compare it to coming out. It feels huge, but two days after you think 'what was I worried about?'

"My mum had no idea I was going through a tough time. I suppose I learned those skills of survival early on, covering up with a camp, fun, confident side."

After all that secrecy, within days he was on the BBC Breakfast couch

"I went from zero to 100 in one go! The overwhelming response to the play was supportive. And once you've worked through your shame and moved through to pride, negative reactions are water off a duck's back."

Told with humour and heartbreak, First Time follows his 16-year-old self, meeting an older man on a park bench, a whirlwind romance, then the ups and downs post diagnosis.

"Looking back, the relationship was quite problematic, he was 10 years older and there's a question mark as to whether I was groomed, but there was never anger just compassion. As I've grown and lived with HIV I think it's inconsequential where it comes from. I never want anyone to feel shame about it or not get treatment."

Hall wanted the show to be "funny and hopeful" not peddling a victim narrative.

"LGBT history is full of tragedy but also joy and amazing stories. All those dramas like Angels in America and the Dallas Buyers Club are beautiful and important but I hadn't seen my story represented. Where is the story of people living with HIV? Not just living but really thriving? What is a diagnosis in the age of medication? You face trauma, sometimes the world feels unfair, but you have resilience. When times are tough and life is hard, the question is how can we support each other?"

As an activist he's aware that stories about HIV are "overwhelmingly about men who have sex with men", and says others need to be told, including the third of people living with HIV in the UK who are women, and the links with poverty and deprivation.

"There's still a psychological impact in having a stigmatised illness. I want a world where it just doesn't matter, where I can get in a cab and say 'I'm going to hospital to get my bloods done for HIV'. There's still a lot of work to get to that place."

First Time runs February 9-13 during National HIV testing week and Camden and Islington LGBT History Month. Visit www.pleasance.co.uk/event/first-time