I'm copy + pasting from Wikipedia to give you some background info. Barbellion was a pseudonym (I feel phony writing nom de plume), his real name was Bruce Fredrick Cummings.
Cummings' life changed forever when he was called to enlist in the British Army to fight in World War I in November 1915. He had consulted his doctor before taking the regulation medical prior to enlisting, and his doctor had given him a sealed, confidential letter to present to the medical officer at the recruitment centre. Cummings did not know what was contained in the letter, but in the event it was not needed; the medical officer rejected Cummings as unfit for active duty after the most cursory of medical examinations. Hurt, Cummings decided to open the letter on his way back home to see what had been inside, and was staggered to learn that his doctor had diagnosed him as suffering from the disease now known as multiple sclerosis, and that he almost certainly had less than five years to live.
Barbellion writes frequently about his death but even more of his will to live.
Cummings/Barbellion, you are so somebody even in death. Reading you, you seem more alive than many of the living around us.
A rancorous, disappointed, morbid, and self- assertive entomologist in a West Kensington Boarding House. Didn't know I was so interested in such men.
Here's an entry to show the humor shining through the sadness of the diary. (That dog sounds just like me when I was a teenage girl):
September 14, 1915
There is a ridiculous Cocker spaniel at the house where we are staying. He must have had a love affair and been jilted, or else he’s a sort of village idiot. The landlady says he’s not so silly as he looks — but he looks very silly: he languishes sentimentally, and when we laugh at him he looks ‘hurt.’ To-day we took him up on the Down and it seemed to brighten him up. Really, he is sane enough, with plenty of commonsense and good manners. But he is kept at home in the garden so much, lolling about all day, that as E—— said, having nothing to do, he falls in love.
I also love this, about death itself.
"To me the honour is sufficient of belonging to the universe — such a great universe, and so grand a scheme of things. Not even Death can rob me of that honour. For nothing can alter the fact that I have lived; I have been I, if for ever so short a time. And when I am dead, the matter which composes my body is indestructible—and eternal, so that come what may to my 'Soul,' my dust will always be going on, each separate atom of me playing its separate part — I shall still have some sort of a finger in the pie. When I am dead, you can boil me, burn me, drown me, scatter me — but you cannot destroy me: my little atoms would merely deride such heavy vengeance. Death can do no more than kill you."
I love you W.N.P Barbellion. It might be of little or no consequence at this point, but who knows, perhaps my own living body contains some of the atoms you speak of. The human condition, the universe, luckily we're all in this together.