I think you ought to seek therapy for your issues from your upbringing. You should also stop doing cocaine and drinking to excess. That may mean making new friends. If you can't stop on your own, that's all the more reason to get into therapy.

You made mistakes, but you did not deserve to have your apartment trashed. It sounds to me like she has issues of her own as well. I do not think that someone who was the saint you make her out to be would trash your apartment, whether or not you cheated on her.

You are young. You can work on your issues and hopefully not make these kinds of mistakes in the future. I would try to find my comfort in taking action and getting a handle on myself.