Gwen - What you're describing is the PTSD we LBSs experience. I think it's worse for you because of the lack of closure with your ex: sudden departure, no divorce etc.
I hit the wrong button on my email the other day and it brought up ancient emails from my ex, dating a couple of years before he left. The emails were full of love and adoration. They rewrite history afterwards, but usually, you weren't crazy. There WAS real love there, until the MLC alien took them.
You're doing a fantastic job with your girls, I know it's been a struggle but you're taking care of business. Now it's time to let go and start flying.