What to do? Stay or go?

[SteveLW]

Do not move out. She wants to leave, she can move out.

Become the best father to your 3 kids you can be. Forget her, and start to move on. Assume she will follow through on the D and stop acting like her H. GAL (every minute you aren't with your kids, you are busy!). Continue to 180 on bad behavior. Make sure your changes are permanent. DO NOT POINT OUT YOUR CHANGES TO HER. Just show them through your actions. Get into IC to help cement the positive changes.

As Cadet's response reads, DETACH. Learn what detachment is (and better, what it isn't) and then work on being detached.

Give her time and space. Remove all pressure and pursuit. Be the best you can be (as ovr said), and just put all of your focus on yourself and being the best dad you can be.