I didn't think I was a doormat either. I was wrong. not letting her control the situation or your life is extremely important right now. going dark and disappearing for a couple nights and an occassional weekend day for the whole day will definitely open her eyes. My sitch has her with OM so really nothing I am doing is helping her work on herself our R/M. But, it has put me on the conversation topic list. I am in control of me and what I do. I deal with everything that I can control and disregard the rest.
You may want to consider taking the kids out for a Dad and the Kids day or movie. do not include her so she can feel what its gonna be like alone. Sounds cruel, but it is the reality of the path she is heading down.