There are a lot of angles here. My gut reaction is to consider a very depressive, gloomy song, but I think I'd prefer to go out with more vitality. Something like Dvorak's 9th Symphony (movement IV in particular), or the finale of Shostakovich' 9th Symphony could provide fitting crescendos. Alternatively, I might consider the vitality of virtuosic composers like Vivaldi, Liszt, Beethoven, Wieniawski, Vieuxtemps, etc. Ultimately, I can't pick a single piece of music that stands above my other favorites.
I'll post another option that comes to mind, because I find the lyrics of this track very fitting, even though it is very gloomy.
"Farewell life and all I died for
now my time is over on Earth
Another journey has begun
Alone I died, not praying for mercy
nor praying for Salvation
A lonely Journey in a Darkened Dream
Time has come to spread my Wings
Slow...
Descending from a Silent sky
Death comes to take me away"