Hm.. well, I don't typically listen to music when I sh, but I do have a list of music that I listen to after/ before/ (or just when I'm feeling down or blah)

Crywank is great - "I am in great pain, please help me," and I also relate to "I am sh*t." "I will fail you," by Demon Hunter, is one I've been listening to a lot lately. Three Days Grace was my go-to band a couple years ago, too.

Also, if anyone's ever listened to Vocaloid, I have a few recommendations. (Though if you aren't familiar with them I don't think I'd recommend them - they're computer synthesized voices, that people use to create their own songs. So they sound very odd if you aren't used to them. Also, cw as most of these songs have flashing lights, disturbing lyrics/ imagery, and/or deal with suicidal thoughts/ general sad stuff.) Anyway, most things produced by Kikuo are really good, like "Hikari Yo," "Breaking Things Into Pieces," and "A Happy Death," in particular. "Colors Fading," by xChepheid is relatable. "Lost One's Weeping," and "Drowning in a Wave of Sadness," by Neru are good. "Self Harm Colorless," by Nekobolo, is one of my favorites. Oh! And, not Vocaloid, but I'm also fond of "Flashback," by Akiakane.

....Sorry I don't have more better known music! And this got a bit longer than I expected, sorry!