Just found about about OM, and.......

[dlt1]

I'm going to give you a dif point of view...but...I don't know that this is good in your sitch. So, think about it long and hard befor doing it. That said...
Have you ever yelled or screamed at her?
If no, then do it now. Call her out and break her down. Make her admit it and press her for why. Ask questions, ask them twice but no more. I don't think you can ignore this. If you still want to be with W, you should address this now. get it out there. You don't have to get all the answers, but need it out in the open. Tell her you don't know if this is ends any chance, but you are open to the possibility.
As I said, not sure if this the right approach. I think it MAY be a good time to stand your groung and show W that you have your limits.
Get more insight before taking this approach. And try for 48 hours before taking this approach.
I feel for you. No action is going to make things easier. You will know what is the best way to address this awful turn. This is time for you to put yourself first.
My thoughts are with you. I wish there was an easy/good answer.