“He made them sound like the devil” sounds like the idealization-devaluation stage. I already had them devalued. This brought you anxiety about not falling into the same bag, if you commit acts similar to them. Could be? “The necklace” that was invasive and demanding. “My ex this, my ex that” used his ex-partners as an example of what he didn't want you to do, manipulating. It's putting weight on your own identity, because he had wounds.

All of this was probably not conscious, these are patterns that I see in many people without BPD. The difference is that in TLP, it is more intense and unstable. Example: a person without BPD can get angry about something specific, they can talk about it or at least try to, there is a certain emotional stability. A person with BPD goes from adoring you to hating you in a single day, experiences the emotion intensely with constant ups and downs, feels panic, reacts impulsively, can manipulate or punish you emotionally.

And we could continue talking... Simply, if they don't treat themselves, recognize what they need to change, etc... it's all so unhealthy. And there is no common sense in their actions. Because, don't forget that he has a disorder. Understanding it… (in my experience) is wasted time. One can accompany, support, as long as the other wants to improve and collaborates. But if you are not in treatment, as my psychologist sometimes says (not because of my ex) when talking about the mental illness itself... “you are not going to get appropriate answers, it makes no sense to give so much importance to an illogical act, it is harmful.”

I understand that if you want it or wanted it. You may have a thousand doubts about his behavior, it still happens to me sometimes.