I’m writing this from what feels like a prison. There are no padded walls and no slopping-out bucket; no jangle of keys, no doors snapping shut against the heavy drone of convicted men. But, it feels far worse. In so many ways.

My cell is not a small squared-off chamber of concrete isolation. It is my own town; my own street - and, more cruelly, my own life. Through the smog of ill-understanding, my family, colleagues and pupils feel like jailers.

Jailers who look at me suspiciously. They are people who know I’m all right to look at, but would find it difficult to believe how things have been.

They have no clue as to my sense of despair. How self-hate feels more real than self-regard; how the idea of death feels more comfortable than waking.

I’m approaching my fourth month away from the classroom. My sick note reads “depressive illness”, but that’s only half the story. This isolation is as bad as the condition at times.

I don’t want a stream of “get well soon” cards. I can live without the sickly smiles of forced sympathy. But what I would love more than anything is to think that I could walk down the street - as my doctor says I should - without the fear of being seen looking “well” while off work “ill”. Being able to sit over a coffee chatting to people I’ve not seen for 12 weeks is what I’ve been advised to do. But how can you be seen outside when you’re supposed to be ill. It’s too laborious to explain - and must confuse people, as I sometimes actually smile.

I am constantly justifying why I am not at work. I’ve begun to doubt my own judgment. I’ve forgotten what “normal” is supposed to feel like.

At present, it’s normal to want to sleep all day. It’s normal to wake at 4am and feel so vulnerable that the grave’s the only place I’ll be safe.

It’s “normal” to be acting out my own death in my mind. The dreams that point me to another day feel like nightmares.

I’m ashamed. It’s mostly childhood wounds that have re-opened. And they’ve become infected. There have been periods of respite - the most was two full days, where the idea of waking rather than dying seemed tolerable.

Things are getting better. The battle is to stay alive. A medical pal told me: “All you do is breathe in, then breathe out; breathe in, then outI ” The thing is , she wasn’t being flippant.

Describing my despair, I feel indulgent; as if I should and ought to “snap out of it”. The fuel tank is empty. If - and when - depression and other mental health issues are more widely understood, I won’t feel guilty for leaving my own front door. It won’t matter to my pupils and colleagues that I can smile but feel suicidal. It’ll be OK to heal in my own good time.

At least I’ve been blessed with a “hospital” sense of dark humour; so it’s “phut-phut-phut” till the next garage and the four-star Prozac.

Martin Grace writes under a pseudonym. He teaches in the north of England.