Believe it or not, you can get back with your ex girlfriend even if you cheated on her. The main problem is that a situation seems so hopeless, that a person gives up and loses all hope of repairing their relationship. There have been some pretty hopeless looking break ups that I may have even given up on, but I have also seen some couples get back together after some extreme circumstances.
My brother in law, for example, was in prison for 5 years (I'll spare the details for his confidentiality). His girlfriend and newborn daughter who is now 6 were not waiting around for him. His girlfriend has moved on, forgotten about him for the most part, and decided not to even allow him to be a part of his daughters life. In the last 6 months of his prison sentence, he made up with his girlfriend, convinced her to dump her current boyfriend, and made plans to move in with her and become a family. I did not see this actually happening to tell you the truth. I observed out of curiosity and to my surprise, he is back together with his ex girlfriend and they are living together. I asked him how he managed to get her back and he showed me a couple of letters he wrote to her.
I will NEVER underestimate the power of a handwritten letter after that.
It was nothing fancy or long or poetic or romantic or even well written. It had spelling errors, was written sloppily, and difficult to read. But, it was personal and made her remember what it was like when he was there. It comforted her and made her want to be comforted by him again. That really is the key.... Remind your ex girlfriend of how good it felt to be with you and she will miss that.... Soon, missing you will turn into a desire for her to want you back. Keep it simple and use you unique style when writing your ex girlfriend. She will relate to it and will touch her heart more than if you wrote a professional, error free letter.
If you are at the point where you are not sure if your ex will come back to you or what you should do to get back with your ex girlfriend.... First of all, DON'T GIVE UP! If nothing else, write her a note or letter. She probably won't com running into your arms right after reading your letter.... But who knows, I seen stranger things..... Your ex girlfriend probably has a lot of things on her mind and emotions that she is trying to make sense of. Your job is to help her by focusing some of her thoughts on you in a positive light. Just be kind, be concerned about how her, be yourself, and her confusion and emotions will settle down to the point to where she can make that decision to give you a call or write you back.
Be patient and be yourself.... I bet when you see her again, you may find out that she saved all the letters you wrote her. Remember, no matter why you broke up or how hopeless your situation may seem, you can get back with your ex girlfriend!