I'm so sorry that you are hurting. Unfortunately, A's do like to see us in pain. They are in their own hell and they want to know others are as miserable as they are. When you are miserable, you are actually doing exactly what he wants you to do. I know it sounds crazy, but your misery gives him satisfaction. It's just the way the A brain works.
The good news.......you recognize it! AND you are willing to DO something about it. Good for you! I know how hard it is not to have contact with him (I'm currently doing the same thing with my A son). But it is the best thing you can do for yourself. Every time you call him or answer his call, you provide an opportunity for him to hurt you again. Stop the pain.
If you do work with him, perhaps it would be best to move on. I own a family business and have worked with my A son before and it's awful. He brought so much negativity to the work place.
Didn't being happy for those few days feel sooooo good!? Just as the habits that were formed while you were with your abf, the "habit" of feeling good will happen if you let it. And when you do, the whole world gets brighter!
gentle hugs