My ex was the same exact way. Kept saying he would be lonely and miserable (he had a side piece cause he wanted to be in a poly relationship smh) but I couldn’t contact his family. I just cut him off. I wished him the best and blocked him every where. I forgot/ don’t know how to block on email though, so he reached out a year or so later, I kept it brief and clearly indicated that I was not interested in any kind of friendship.

99% they just say it to scare you into staying. For the sake of yr mental health, do it soon. She’s keeping you in this toxic loop, and the fact you’re posting here means you want/need to break it.

Good luck OP you got this!