She was very close to becoming a WAS like you are. I don't think her H ever had any affairs, but she wrestled with a lot of the same issues you are. I think you'll relate to her struggles. She has been reconciled with her H for quite some time and now spreads her wisdom and unique perspective across these forums.
And like Karen said, do read DR, you'll find it helpful. A DB coach can help as well.
I can understand why you don't trust your H right now, he has really violated your trust multiple times. He sounds like a serial cheater. Your M can recover from that, but it's a long road to recovery. And if you do decide to reconcile, I would make it clear to your H that he gets no more chances. If he chooses to have an A again then he's out of the picture for good.