I know that feeling. This is what narcs do - the surprise attack can come months, a year, or even years later.

I too, am learning how to strengthen my boundaries. It can be really hard, especially when you may secretly want to keep hoping for change in a person or some kind of epiphany. Narcs do not change nor do they have sudden eye-opening epiphanies. Their entire M.O. is to seek and maintain power and control - months later, even years later. Narcs hate being dumped and they will stop at absolutely nothing to regain control and/or to get revenge.

The sickness you describe feeling is a result of this surprise attack. Next time, you will know what you need to do to protect yourself and the kids from another surprise attack.