I had an ex that would bring up the past a lot when ever we fought and it was always what I could have done or should have done, and at first it didn't bother me, but then I just felt worse and worse about everything even though I could not change anything I would hate my self for anything he said I did wrong.

Try talking to him and telling him how you feel and if it hurts your feelings, and if he still brings it up, he's never going to change, and you don't deserve to be berated for something your not able to change.