I agree, he's just too interested in what OW is doing, and just too jealous sounding when he talks about her other R's. Hopefully this will all just fade in time, but I think it was pretty darned insensitive of him to compare your letter to hers!!!!
It does take a while, though, for that fantasy to fade. In the meantime - I think the key to getting through this is to A) continue to work on 180s and personal growth, be that fun and interesting partner, keep to your workouts and diet, and B) paradoxically, start thinking about putting yourself in a position where you would be in good shape even if he left.
I say paradoxically because usually, we shouldn't look where we don't want to go (just like riding a motorcycle). But it seems to me - if your finances were all in order in such a way that you would be fine financially if he went off the deep end again, if you felt really fit and attractive and secure that you could attract new love into your life, if you had a life full of friends and activities - that you would be less frightened about whether he does or doesn't stay. And you would be more attractive to him, and he'd be more likely to stay.
