OP, I personally believe that some abusers can abuse without consciously realising it or deliberately setting out to abuse. Obviously some do, but I think others are psychologically messed up/deficient and lack the emotional tools to let themselves face up to what they're doing to you. Or it's all part of their (terrible) coping mechanisms for dealing with their own pain.
Others may disagree with me, but this is based on my own experience. And I know it makes it very, very difficult to leave the abuser. After all, he's not a totally evil psycho who wants to destroy your life--he wants to have a happy relationship with you. He just keeps screwing it up whenever you let him try.
I don't believe these men can change--or if they can, the likelihood is so small, it's not worth the risk to you. It is much safer, happier, and healthier to move on with your life and not remain caught up in his terrible cycle, no matter how good it may look when he is in the "nice" phase.
As a matter of fact, it's kindest to BOTH of you to go ahead and draw a line under it and move on with your life. He needs serious help to improve his own behavior and he just won't get that if you keep letting him suck you back in--why would he, if what he's doing works for him?
I've heard it takes an average of 7 tries to break free of an abusive relationship. So you're not an idiot or deserving of abuse if you've had trouble breaking free--but please do listen to our advice, OP. Take it from those who have been there and leave him for good if you are able to find the strength.
Focusing on yourself getting better is a GREAT idea--prioritize that! If he has truly changed his ways, he will understand AND RESPECT your need to do that, and he won't pressure you to do ANYTHING that you feel doubtful about, whether that's living together rather than just dating, or taking a break altogether while you work on yourself for a good long period of time. If he can't take no for an answer on ANY aspect, he is still trying to control you and that is abuse, whether he's doing it from being evil or from being pathetic.
Also, you should never be asked to forget the past. What you're doing when you remember the past is not dwelling on resentment and refusing to forgive (abusers love to trot that accusation out). You're actually learning from experience and being smart if you don't forget the past. You are doing a lot of the right thing, OP! Just keep doing that part!