There is no quick fix for a relationship shattered by betrayal. If things are ever going to get back to some kind of “normal,” it will take a long, long time. If you want to remain aware of your girlfriend’s feelings and her importance to you, then don’t forgive yourself, yet.
Let your guilt guide your conscience and be a constant reminder to behave properly and treat her with respect.
That said, you do not want to be apologizing all the time or allow her to disrespect you constantly either. Let your actions and demeanor show her the man you really are.
First, of course, you have to get her back. She might not take your calls or read your texts, so you may have to figure out who can help you get a message to her.
Her mother probably isn’t interested in taking your side yet, but maybe her girlfriend or the girl of your best friend could at least tell her that you feel terrible, are very sorry, and that you just want to have a cup of coffee with her to tell her in person.
Don’t bombard her will calls a hundred times a day, but do make a serious effort. You have to find a way to sit down with her, just the two of you.
Give her a little time to be furious and devastated. She has some healing to do, too. If you can catch her in a good mood sometime, have a short and sweet statement prepared to communicate the key points you want to mention.
If you are fortunate enough to get a few minutes of her time, just talk. Keep your hands off of her unless you want an elbow in the teeth. Don’t expect her to be able to be in the same room with you again for a while, and don’t call her today or tomorrow.
If, some day in the future, you have again earned her trust and respect, she may find it in herself to forgive you, forget this terrible incident, and put it totally behind her. Then, when you are once again the light of her life, the bounce in her step, and the joy in her smile, that’s when you can begin to forgive the better man you have become.