I'm going to end a friendship I believe is bad for me.
Why do you think it's bad for you?
They involve me in their problems and complain all the time.
Ending this friendship sounds smart. It's okay to give up on a friendship that isn't healthy.
I'm a piece of shit and doesn't deserve friends.
Why do you think that you don't deserve friends? Maybe this bad friendship has affected you negatively, and you should separate yourself from these people.