Friendship breakups are brutal. They're so much harder (in my experience) than the vast majority of romantic breakups. This poem captures that agony beautifully.
I cut my ties to my best friend of over 40 years 18 months ago when she opted to treat me like crap, all because another friend couldn't own her mistake about something. She took that friend's side, and it one of the most stupid things to put a friendship on the line for, but she did. And I called her bluff in the end because I deserved better.
It sucks. I'm sorry you had to go through this. It's clear how painful it was by your words.