If your W is still in full affair mode, the performance she is giving is the one she is playing and believing in her head. She thinks, "I love these kids, and it is so sad that I don't love DCBM anymore. I wish it were different. I really love these kids, but I can't stay in a marriage when I don't love DCBM. He had an affair on me, too. He knows we don't belong together deep down, but won't admit it. I'm doing the hard thing, but it is for the best." MIL is believing it because she doesn't know any better and feels bad for you as well, ...but what can she do? (she thinks)

You know this, but I will repeat it. Your wife has the foggy mind of someone in an affair. Their thoughts are unclear because of the feelings they are having with this new person. She is thinking how much she feels for this other person so she can't possibly love you. It's all wrong, but it is what is going on inside of her.

The attack she had against you and the stories she made up and her trying to take your D away was one of anger. WHenever confronted of what she TRULY is doing, she is going to respond in anger. It helps cover what is truly happening. When the fog clears, there will be extreme guilt. Whether she admits it or not.

I know you are focusing on your daughter, now. Which is what you need to do. Your W needs help. Keep focusing on your daughter, but don't give up hope that your marriage can still be saved. It may not be, but there is still hope that it can be. You reread the book which is good. Work on yourself. Think about the things that you need to improve on and do those things. Look good, smell good, be the man you want to be. She WILL notice. If/when she wants to come back, you have all the things you need ready. You tell her those things and if she truly is ready to come back, she will do them. First thing being to get psychological help (if she truly has those issues), second "no contact" whatsoever with the OM, and third some sort of counseling. You probably think this information is not important right now, but you never know when she may come around.