This may sound harsh but you need to get over yourself dude and stop feeling sorry for yourself. There is no reason to be getting so angry, punching holes in walls etc. Doing that shit is more off putting than you think your stutter is. You have to realise no one gives a shit about your stutter, you're the one holding yourself back. Its all in your head! The only reason your relationships are bad is because you've made them that way. Don't let your stutter define you!...be a good person, stop getting so upset over things you can't control, try to build confidence in yourself, smile more, laugh at yourself. Good things will follow.