Is tough dude, but you got to stand up and lift up your face, you have to show all the scum you are a better person, and you are human, you have lived difficult stuff, and managed to survive the hard, you still here, try to look forward, fuck your fiancee dude, fuck her, who is she to make you feel like that, she must feel worse and want you to be with her in her feelings, that only thing made her miserable, you don´t need that, to fuck with everything about her.
Look for the future, look for friends, there`s still good people in this world, people to make you feel good, go and hang out, focus on a new band, you are talented, start making new music, come on dude stop running in circles with your old life, you have to live a new one, a better one, and is just around the corner.
I wish you nothing but success, and i know you`ll have it, and soon you`ll be making thread about how you are feelling with your new band, you found a new girl, etc.
Smile dude, go take a walk.