Your story sounds similar to mine. In my case, my H moved out nearly 6 months ago, after talking & texting her in front of me for 3 months. It was hard having him move, but i think it will help in long run. Our H's need to work thru this on their own, in their own time. We need to work on us. More than likely the novelty of the A will wear off & then you will have a chance to possibly work on your M.
I think your H is getting his cake & eating it too. He has made it clear that he thinks he loves her now, not you. Believe me, I know how painful this is. But, why would we want to be with someone that doesn't want to be with us. Work on detaching from him. Let him see what he is losing.
This takes time & TON of patience. Keep reading & posting.
