FWIW, it sounds to me like you're attaching a lot of stuff to the "selling of the house", stuff that's making you an emotional wreck. All he said was that he wants to "talk" about selling the house, and you're spinning it out to last September and a bunch of "what ifs" and "no way is he gonna live here with her!" and it's obvious that this mode of thinking is what's causing your grief. Instead, can you take a deep breath, let go of that tainted crap that only poisons you, and visualize this upcoming conversation in a just business view?
There's a difference between talking about selling and actually having it sold. And if you're on the title, he can't sell it without your signing off. Worst case if it gets sold, you could end up with a nice amount of equity or a promissory note, best case being you might even very well find that this opens a new door for you yet unseen.
