Once you are an EX, we girls normally do not go back with you because there were issues in the relationship the first time. We broke up with you for a reason and vice-versa. Why would we want to do it all over again? If you want this girl back then fix the problem that she left you for and see if she comes back. If it was for something you did majorly wrong then there is a huge chance she will not come back. Hopefully you will learn from your mistakes and again vice-versa.
Sorry if this sounds bad but I'm really trying to help.
