Your W is taking the issues and using them as an excuse to run away. As with every WAW/MLCer she thinks the grass will be greener on the other side. Ofcourse it is not.
My personal tactic is to not stand in her way. Let her find her own way. Let her find out what it will really be like. I do not make suggestions to her about her actions or try to influence her in any way. You cannot control her, so don't even try. Just validate her feelings and let her find her own way. Be assured that the A won't last.
I spent the first 3 weeks doing what you are doing. Freaking out and pushing her for answers and commitments to work on the M. It just got worse and worse until I stopped and decided to just be nice to her. Since then, she has not yet returned, but thing are getting better. She now calls me or emails me every day, she lives in a little dump of a place, has no money, has a POS car and is having panic attacks. I just keep being nice to her and being there for her.
Take some time and read the resources on the MLC forum. See if they fit your W.
Understand that you are not likely to fix this any time soon. The problems didn't happen over night and they won't be fixed over night either.
M35 W37 S9 D6 M12 yrs Know 15 yrs Bomb 1/28/07 My Sitch Failure is the opportunity to start again more intelligently - Henry Ford