Yeah, that'll certainly do it. Sorry to hear that.

Sounds like your stepmom is always in the back of your mind and those negative thoughts just get triggered by things like this. (Nothing wrong with watching these types of movies, btw. Just saying that sometimes these things can trigger us.)

Are you doing EMDR? I wonder if you need some sort of closure. Like, there is something in the back of your mind that is not satisfied and so it keeps coming up again, and again, and again. Not sure if I have advice for that, but obviously if you're able to do EMDR (or you're already doing EMDR), that could be a good approach.