Aww, uber, I feel you
. When my mom told me that my ex had conquered me with his cats (he has 3 british cats, they are beyond awesome and cute), I had to agree there was a lot of truth in her words.
But as for the other parts, Angela is right: now you can consciously see how your new attitude affects your feelings about your decisions and thus eventually the decisions themselves. This event has shown you that your new life is worth pursuing, since you feel bad about the old behavior and know that you would have felt better choosing your new behavior. The whole "choose things that feel good" perception actually works.
As for the ex, I would say that chances are slim that he will change, thus chances are slim that you can remain in relationship, but you can always give him a chance and show your new way of thinking through action, to see how he reacts to it. If he will not update his actions, you will eventually feel so "incongruent" and unhappy with him that you will be relieved to break up with him. Of course, it is better not to get there, but if you need that lesson, you will choose to have it.
Have no fear
You are on the right path!