Jesus... Dude you gotta stop talking to her... That is brutal; prob why you still feel like shit after 2 months.
That doesn't mean you have to hate her, or treat her badly. But just stop talking to her and if she talks to you just tell her respectfully: "talking with her is making you miserable and unable to move on and for the time being you would like some space".
I know not talking to her may be hard... But you guys broke up, and when you talk to her and you guys converse like nothing is wrong it creates a sense of false-hope that you may get back together. And it is that false-hope that is ultimately making it impossible for you to move on.
So in conclusion, end all communication with her, honestly I would suggest blocking her on Facebook just so you're not reminded her as much. The first couple weeks will be most difficult, I suggest keeping yourself busy hanging out with friends or whatever your hobbies are. Whenever you feel ready start looking for other girls, from drunk hook ups or formal dates, the thing that ultimately allow you to move on from your ex is to find someone else.