For being slightly macabre I think that you had a very good idea and you ran with it. I think choosing a first person narrative was absolutely the best choice for this particular style. I can almost envision myself sitting there holding my head replaying the recent event trying to understand everything before I passed.
Very original, love it.
There are a few things that I'd like you to look at. The tense in which you are writing here changes from past to present quite a bit. If you are going more for a "before I die" concept try to aim more for the present, if you are going more for "I have already died" concept I think that you might want to reevaluate your tense choices.
One that I would change is "I sit in pain till I died, " I would change that to "I sat in pain 'til I died,".
It's also slightly confusing at the end there
Til I died
I may die
I had to die
May want to rearrange the order of those
Also, on a completely separate subject away from tense, you are very repetitive. When you see you are using the same word 10 times and it's not something mundane like "the" or "a" you might want to try synonyms to get a greater effect or reaction.
Overall I believe with a little polish this could be very, very good! I hope you always keep such a vivid imagination!