Go talk with a lawyer as soon as possible. Her history shows that she most likely has seen one this time. Don't fear it. Knowing what the process might be like is empowering. Given that you are a STHD, knowing your rights around spousal support in your state will only help reduce your stress when you think about being on your own and finances.
Great job on not taking her idea of having you be her nanny. As hard as it may be, you will have to show her what life is like for her without you for her to have any appreciation and respect for you. And don't let her control you with that abandonment stuff. That is her issue to work through. That is no excuse to treat you like this.
You can do this and regardless of outcome, you and your kids will be okay. The only thing you have to fear is fear itself.
