I believe I've said this to you before, but here goes again.
It's not about trusting *him*, it's about trusting *you*. When you get to that point, it really doesn't matter if if's genuine or not, because you will know if you can live with him--as he is--or not. The sooner you stop trying to figure out whether he's really sincere this time or not, and start figuring out what is acceptable to you and what is not, the sooner you will find the peace you seek.
L