Ed Coleman is an actor, improviser and writer and last year he lost his father. Leave a Message is a part-verbatim hour of what happened when he had to begin the unenviable task of trawling through the squalid wreckage of his father's flat. Here Ed talks about what inspired him to write a comedy about a (mostly) true story (written and performed by Ed – the guy who lived it) and why he feels it's sometimes important to peer into the detritus of a life, death, family secrets, alcoholism, our legacies and loneliness, and asking will any of us be remembered for anything more than the mess we leave behind?

I never really intended to write a play about my father. I thought I'd got the writing out of the way with his eulogy, scrawled as it was in a febrile 90 mins in the lobby of the Jury's Inn, in York city centre. I was bought the time to do so by my dear friend Pete who valiantly engaged my mother in conversation on a range of topics – just so I could do something I wasn't looking forward to and really should have done a week before. This was my Chemistry GCSE all over again. Technically I couldn't fail this exam – and in fact I thought I'd passed with flying colours – I'd said the things I wanted to say, and I'd performed it with (if I do say so myself) aplomb. It was only in the weeks and months afterwards, as I started having to tell acquaintances – who I liked, but were not the close friends who saw me through it all – about what had happened, that I realised there was maybe more of a story I needed to tell.

There was the sadness of his demise: naked, alone, on the floor of a bedsit, dead for days before his body was found. The sadness of his story: a 30-year battle (although he never admitted as such) with alcohol. A once brilliant mind squandered. An extraordinary potential unfulfilled.

There was the practicality of the aftermath, when I had to go and empty a flat that was currently not being paid for, as benefits stop the moment the death certificate is signed. I would have done this alone, had it not been for incredible friends who insisted on coming with me.

credit: Ali Wright

Then there was the madness of what transpired while I was there. The comedy of my being so insistent on recycling that I drove a bin bag full of pornography to a Morrison's car park. The tragedy of his loneliness manifested in the discovery of his addiction to commodified companionship – one which had taken him into irretrievable debt. The twin demons of alcohol and solitude, feeding into and propelling one another round and round like a self-immolating Catherine Wheel, until eventually the powder ran out.

And what did this say about me? The play takes its name from the voicemails I listened to that had been left in the days that he had been lying dead. Almost all of them were from my mother, a testament to her enduring kindness and empathy, despite having left him 30 years before. None of them were from me. I'd had the vague charitable notion that I'd call him once a week, though that easily became a fortnight, a month, two months, or longer. In the past 10 years I'd spent no more than 8 hours in his company – half of which were when he was hospitalised with cirrhosis. I was told he was about to die, so I went to make my peace. I felt I had, then he had the temerity to survive. It was all a bit awkward after that.

When he finally did die, years later, I was surprised by how sad I felt. The sadness quickly became guilt, and the guilt was easily deflected by anger. Particularly at these women who had taken what little money he had, just to speak to him on the phone for a paltry few minutes at a time. But as I dug into his possessions, a bigger picture emerged – correspondence, comfort, fondness, sexuality and banality intertwined. A mutual appreciation beyond the transactional. To the point that I felt duty bound to inform them of his death. One even called my mother, having not heard from him for two weeks. Apparently, he had given out his ex-wife's phone number as an emergency contact. The two women talked for over an hour.

credit: Ali Wright

It was this part of the story that fascinated people most of all. In particular, a man called James who I met at a house party, and regaled with the whole affair in lieu of making small talk. I told him I was thinking of writing something, not only about my father, but about these women who had touched his life, and the friends who continue to fortify mine. But also about me, my own demons, my failings as a son and my fear of suffering the same fate as my father. It turned out James was a writer, and he offered to help. Which is just as well as I couldn't have done it alone.

The result is Leave a Message. It is of course incredibly personal to me, but its story speaks to many things beyond myself – grief, hurt, love, friendship, family, helplessness and hope. And humanity. In writing of him I have found an empathy for my dad I thought had long expired. I am grateful for the kindness he was shown by those women, beyond what they were paid for. I'm oddly proud that his demeanour – addled as it was – had elicited such a reaction. I'm still trying to figure out what this says about me.

In the end my father's death, or at least the manner of it, has had an almost inappropriately positive effect on my life. It brought me closer to my friends, made me confront things in myself, brought an extraordinary group of artistic collaborators into my life who it has been a joy and a privilege to work with. And it has enabled me to create a show I'm proud of. It's the best bit of parenting he's ever done. Shame he's not around to say thank you to.

Leave a Message, Gilded Balloon Patter Hoose, 3–26 Aug (not 12), 2pm, £9–£10 (£8–£9). Previews 1 & 2 Aug, £6.