What a wonderful post, just what I have been struggling with in my own situation. I did look at his life at face value, seeing that he has someone and I am choosing to be alone right now. But then I realized he is spending all his time with her talking about or to me, his lies to her about his history and lifestyle-she doesn't even know the real man I had for all those years. She only knows the alien shell of depression and anger. (The little info on the side in which I became the other woman was a real eye opener as you said.) So I am being quiet and continuing to listen and laugh at some of the antics.
But for a time I wondered if I was the crazy one as he said. When one of his oldest friends came to me and said he is off his rocker, I felt so vindicated. But now I feel only a bonecrushing sadness for him while I wait for his world to implode further so that the fallout does not destroy me as well.