I'm sorry to hear your situation has turned for the worse. Mine has as well, and our situations sound so similar. Ages of our girls, The BS our wives are telling us, etc. The only difference is my wife fell in love with a single man younger than her. (of course she says thats not the reason)
I don't think you and your wife are over yet, however until you GAL and start living your lifes puporse, she won't be able to see what she had. It's unfortunate that she has to go on this journey alone, but its something she is going to do. You will not be able to convince/reason/negotiate her out of it.
Do what's right for you right now. Make sure you and your girls are safe.
If you haven't read any David Deida books, I think you need to go out and get 'The Way of the Superior Man' today. You are at a transition point in your life, and its time you stepped up and started living your life again.