General relationship BS.

Every relationship I have ever been in has ended badly. I've be played, looked down on, friendzoned and most recently, cheated on. Worst part is I keep having feelings for the girl who cheated on me several times. I don't know what to do but I keep feeling myself caring about her. I know I just need to move on but this has wrecked my self confidence and ability to keep going. I feel like I'm living in the Offspring's song... "well I know, I'm being used, but that's okay man cause I like the abuse. I know, she's playing with me, but that's okay cause I've got no self esteem."