What are you doing? In an earlier post I gave you a bunch of suggestions have you considered them?
You say your commutes home are terrible, then listen to books on tape, or a podcast. Get your mind off her.
From my experience the guys that get their wives back are the ones that work hard to build strong lives with or without their wives.
To me it sounds like your mother in law is enabling her to run and destroy her family. It doesn't mean you have to declare war on her, just keep in mind that things will be harder for your sitch, because mom will probably pay bills, and babysit so that your W can go be irresponsible and further develop her EA.
So why should she go back to you? She will have financial stability from mom, a better caretaker than you, and can get herself other men.
Do you think she'll go back to you because you are begging and pleading?
It's time to work on yourself, and to not worry about her.
It's simple eventually reality will set in on her and she may realize that she is not better off without you. Then she'll look at you, and see how you are doing. If you are doing better there is a better chance she'll realize that you are a good catch.
Look I'm not tryin to be a jerk, but she is leaving because she thinks she can do better than you. Prove her wrong.
