i keep almosting cheating

since me and my girlfriend started going out every couple of months i thinking about cheating on her with with her best friend and i know i could never cheat but she thinks that thinking about it is just as bad as cheating and she left me and i really really want to change so maybe i can get her back and i hate myself so much for having those thoughts. i've always hated myself because everyone has always hated me except for her and shes always been there and i dont know how to act to being loved by some one. i really miss her but i've made my own noose with this. im willing to listen to all advice anyone can give because i miss her so much i just wish i hadn't been so stupid and thought that way.

i can never orgasm when we have sex no matter what kind, im terrible at sex, i lost my virginity to her and i've never loved anyone as much as her shes the only one whos ever been there for me when i was upset about something and now i've lost her im so stupid i want to do everything i can to make it up to her and get her back but im not worth her time.