John, I can see how you want to understand why your W says or does some of the things that are so hurtful. Making the H out to be the bad guy, and rewriting the marital history is at the top of the list. I was a WAW who did the same thing, and yet I doubt I could explain to you where you could understand to your satisfaction, B/c John, you still think of her being the same person she use to be. There is the conflict in your understanding. It makes no sense to you, right? It is not logical. Even after you do a lot of soul searching, you cannot understand her. Sometimes, there are things in life we never understand....and this is one of them.
She is going through an emotional crises. Trying to decide if it is a MLC or whatever is not the point. It is a crises, regardless of her age. She may, or may not, not show it, but she is experiencing her own brand of pain that you will never understand.....and I can't explain it well enough.
Years of stress, unfulfilled expectations, unmet needs, etc., is handled differently by individuals. She may appear to be a strong, loving woman.....but somewhere something broke in her. Perhaps it was more like a slow death for her, IDK. But she is broken and trying to find her way to some happiness for the remainding part of her life.
She doesn't want your help. She doesn't want to be around you. She is full of resentment b/c she wanted and needed more from the M than she got. Now I am not discussing fairness. That's not the issue with her. The issue is she didn't get what she wanted, and now she doesn't want anything from you anymore. Her feelings for you have changed. She is different now.
Her brain and emotions are overwhelmed with negativity about you and the MR. Maybe she needs justification for leaving, maybe she needs others to side with her, or maybe she is just so angry and frustrated that she has to have a target to aim all this bad stuff toward......and you are the target. Something caused this to happen in her. Maybe it will surface eventually, or maybe it won't. But you will not be able to resolve things until she can get rid of the resentment. She will need space and time. The fact that she is "dwelling" on it, means she is really, really angry and can't figure out how to feel better. Again, you are not the person she wants to help her.
People who really know you will not believe what she says about you. You have to realize people will believe what they want to believe (without any proof to back it up). I know that's hard, but there's really not much you can do about it. If you get into a grudge match, that sure won't make you look like a strong, confident, man of grace and honor. You can't help what she does.......but you can help how you choose to respond.
I hope someday she can find herself again. It is up to her.
A lot of damage can be done in the heart of a woman, and her H not have a clue anything is happening. Sad, isn't it, that couples can't relate to each other better.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!