It is sad
This was a sad song if only because of its title. It's funny because a lot of times people wonder what is going to happen at their actual funeral. A pity they will be, kinda dead when that actually happens. I recall seeing George Carlin's standup about what would happen at his funeral shortly after he died. Many of us envision what song we would want to have played there. I don't know if this is the one for you, but it certainly fits the funeral theme.
It's great that this can all be done with a piano as I used to be an avid piano player. The fact that I stopped is perhaps all the reason why this song is depressing. At least you put it in an original feeling to your work. It can get a bit forceful at times, especially the end. This is where it works best, because it brings closure to the piece.