I learned all of my emotions were there for the good reason, including the ones I disliked having and wanted over with ASAP, as I considered them to be negative, as they made my pain even worse. I found out I can learn from my emotions, if I face them with openess and honesty. If I answer all the why questions. But why questions about me, not my AH.
It's a process, hard one, but worhtwhile.
I'm afraid there is no shortcut through this process, but it can be a learning experience, and what you learn from it is how to be happy again, as you finally realize your happiness is internal thing. For me the big step in a good direction was to stop blaming my AH for my unhappiness. His actions were making me miserable in my life, so I had to decide whose fault was that: his for doing it, or mine for letting it happen. With first desicion I'm stuck in misery and can't do anything about it, but if it's second than there is so much I can do about it and move on.
Also, very important for me was to let go of what I considered normal and right and moral in terms of how other people should behave to me, and I started only doing things that were right and good to me. So to say I let go of expectations and went for action instead, but action in regard of things I can control.
That freed me of my resentment and anger, and that is something I'm very grateful for in my life.
Judging by what you said I think even though he's out of your life you still have expectations of him, that you kind of expect him to change something that has happened or gives you some kind of appology that will make it all up, but you know there is no that kind of appology, nothing he can do or say to change it, and I think you know it and it's making you angry. So IMHO the only way for you to move on is to stop expecting anything of him, even more to stop holding him responsible, as it is only hurting you.
I guess it's a forgivness thing, forgiving doesn't mean forgeting, but it means setting yourself free.
This is my honest opininon, and I really hope it is not too much for you at this point, and i really hope you might consider it.