How can i get my girlfriend back?

Well shouting isn't going to help anything. The first thing I'd work on is your anger. Take some classes or google little ways to practice controlling your temper. Show her that you are more gentle and mature (which is a good trait in a guy) And start from scratch with the whole "flirting" thing and doing little nice things here and there. Show her that you are patient, and don't pressure her or rush things. Just slowly become her shoulder to cry on and start as a friend. When she becomes more comfortable with you as a friend she might start reconsidering things. Good luck! Hope this helps!