You want her to stop the D, and want her to accept her part of the breakdown, but to keep standing your ground? IDK how to word such a message, without pursuing.
You: " Would you agree to join me in seeking professional help to save our M?".
WW: "You said no more contact!"
You: "Will you consider stopping the D and work with me in getting professional help for our M?"
WW: "Will you admit everything is your fault?"
You: "Can we agree to not blame one another and get the help we need?"
At this point, it is getting very pushy. I just don't have the perfect dialog scenario for what you want. Maybe someone else is more qualified to word what you want.
My heart goes out to you, truly. In all honesty, I think you are feeling panic b/c the D date is coming quickly, and the realization is scary when you are so emotionally attached. You've not had sufficient time. Once it is official, then you might feel some emotional relief, IDK. At the moment, you feel desperate to "do" something. I think I can understand anyone experiencing those feelings.
I don't believe you've really heard the last from her. If nothing else, b/c of her mental issues and instability. I think she's having a difficult time, just as you are. You know, she tried to talk to you several times and you refused. You saw it as standing your ground? Anyway......if she calls again, maybe you will want to hear from her...or maybe you will want to move on.
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!