You want some real advice.

Let her go, if you act like you don't care and don't always try to call her and get out of her life she will start to miss you. Right now she is mot missing you because you haven't really gotten out of her life, and she feels she hasn't had a fair shot with this other guy yet because you are still around. So if you just leave her alone she will start to realize that you mean a lot to her and really miss you and she will come back to you, garunteed. Happened to me multiply times.

Also, don't beg.