It sounds as though there are a lot of feelings that haven't been dealt with. What has happened in the past is exactly that....In The Past! But, obviously has not been forgotten. And, without acknowledging the feelings, you can't move forward. There is truth to everyones comments here; from counseling to moving on.

Without sometype of closure, your never going to have a healthy, truly fulfilling relationship in the future with the girl, and will even carry on to future relationships (if any).

As much pride as you may have to seek the help of a counsellor...please think about it. Pride is the crutch of the insecure!

Good Luck Sweetie!
HUGS!