Welcome to OOTF, Fogs. I can very much connect with what you are saying about that feeling of dread. I was married for 22 years to an ASPD husband, whose regular rages, threats, coercion, lies, and manipulation made my life miserable. I’ve had no contact with him for 2 years (now divorced), but that doesn’t mean he’s not in my head regularly. For the first year, sometimes it felt like I’d never stop feeling fear and dread, but it has slowly reduced — and that took a lot of work, learning, etc on my part.
OOTF is a great resource. I think you’ll find many people here who have experienced (and are now struggling with) the flood of feelings and thoughts left behind by marriage to a PD.