Running.
Been doing it for years, on and off. I'm good at sprints but that's about it.
Music. It used to help, now it doesn't, because I think "Holy shit, how pathetic are you being? Stop it."
Sometimes, just thinking about it, like, knowing you're better than how you're acting. You can tolerate things, and that you've accomplished a few great things. Even if people think it doesn't matter, but hey, it might mean a lot to you.
Just stop and look at your situation from an outsider. It's not always so bad. She doesn't mean everything in your life. It's okay if you do a few things wrong the first time. Hey, be glad you had a place to sleep tonight, you know?
Things like that.
Some people have it worse than you, and some people have it better than you. Take what you have, do what you can, and just realize that most of it doesn't matter much and that you just need to calm down and be happy with what you have.