STOP!!!!!!!! Here's the extra issue with you, which is not unique: OW and his life with her. It would kill me to be thinking the things you are probably thinking about. With my H and his OW, she didn't want to hang out with him. The few times he saw her outside of work.....it was a work function with hundreds of people around, so it was like being at work. She just wanted to flirt with him at work and not much more. His ego is still smarting from that realizaion. Plus she went and found a boyfriend almost immediately after being dumped by her ex. And my H took that pretty hard too....I told him, she had the opportunity to pick you and it never even crossed her mind. He knows that too and is dealing with it much better I must admit.
But anyways--your situation SUCKS the big one. I feel for you so much. It's agonizing. But you will get through this and he will regret his decisions he's making now. You won't.