I wouldn't try to cast any kind of judgment on you or your relationship with your ex since not really knowing you or your ex, but what I might suggest
sometimes its just best to close the book and let life carry on and at least make that relationship a definitive learning experience for the betterment of yourself.
There are plenty of good girls out there, how about focusing your attention on finding one, and in the mean time make some of your personal advancements
with the attention of increasing your self confidence......... keep your chin up and look forward. good luck