Welcome Sodga
I agree with the others.
If you have anger problems, then you really need to sort them out. Marriage won't do that. It could even make things worse.
If your girl has become your ex because you have lashed out at her, then marriage is not going to seem like an attractive option for her at this stage, anyway.
It is good that you have acknowledged your problem. That is a positive step. But have you acknowledged it to her?
I, like the others, would recommend some kind of counselling / therapy. Ask your doctor for advice.
I think, if you want this girl back in your life, that you need to apologise to her, tell her that you are addressing your problems and let her know that you are getting some help.
It's probably best done in the form of a letter, in my opinion.
Good luck!