From the few artists I know in this thread and any self-descriptive titles, this is going to be rather out there but…

Breaking Benjamin and Three Days Grace are what a friend and I agreed is the perfect breakup music. I think it came up because it made me feel better during a breakup but I didn’t want to continue listening to it to avoid getting sick of it and it losing the effect next time. Or something, idk I was a teenager :p

BB: I will not bow • Crawl • Blow me away
3DG: Break • Scared • Riot

Didn’t know them at the time but Amity Affliction probably fits here as well. Soak me in bleach or Pittsburgh, for example

You Outta Know by Alanis Morissette

This is not a breakup song, but about many things i think. However the allusions to loneliness (or maybe solitude/isolation rather than loneliness) have me slot it partially in the breakup category… “Reckoner” by Radiohead.

Too Bad by Rival Sons

Joey Dosik, Vulfpeck - Running Away https://www.youtube.com/watch?v=wvpLjcXU3hY&t=222

Smile by Lily Allen (the music video is unhinged)

Self Destruct by Between Friends (totally hinged)

Baby Bitch by Ween

Dry your eyes - The Streets

If you’re the one who wanted to break up: Want You Gone. The song Glados sings from Portal 2.

If not: 50 Ways to Say Goodbye by Train

Ok just thought of another one that will be good if you like country that is pretty twisted.

https://www.youtube.com/watch?v=UJzp4ljVDi0 David Allen Coe - stains on the pillow where you once laid your head

Unbreak my heart - Toni braxton

Its not right but its okay – Whitney Houston

Before he cheats - Carrie Underwood

Before He Cheats but the mashup version with Warriors.

Jimmy Buffet - Margaritaville

Not enough songs out there for the people who know they were the problem.

Type o negative - anesthesia

Def Leopard - Love Bites

Theory of a Deadman - The Bitch Came Back

Train - 50 Ways to Say Goodbye

It’s hard for me to pick just one so I figured I may as well toss in a few to fit a couple moods.