It may take a long time to really see it, but not being in this relationship is the best thing that could have happened. Your ex-boyfriend sounds emotionally abusive. It's not normal or healthy for one partner to badger another about things that happened in the past. Not all guys are like that. Now you are free to meet someone who will accept you and treat you kindly.

Remember when he comes knocking at your door again that the drama can be very addictive. Breaking up and getting back together feels good in a weird way.

You are good enough. No matter how hard you try, he will always make you feel like it is your fault. That is the real problem with your relationship.

If you do get back together with him, I would tell him that he needs to stop blaming you for everything that goes wrong and stop harassing you about your past.