You might also find he doesn't actually care as much as you think he does when you get away. Cluster b personalities (oh hi) often have something called "relationship impermanence" where you'll just kind of stop existing and he'll lose interest after he hasn't seen you for like 3 months.
Not that he's consciously lying about that specific thing or anything; part of why we give that vibe so strongly is that we also truly believe that nothing will ever matter more than you while it's happening. Cluster b's who have done therapy have to specifically learn skills to stay invested in relationships long term but I'm going to go out in a limb and guess this person has done 0 therapy and has no intention.
This isn't to say you shouldn't take any of the precautions other people suggest because you absolutely should just in case. But don't look at it as this impossible inescapable thing when that's probably just part of the "spell" of control he's got you under psychologically.
I don't wanna frame it as "I'm too smart," but I think I have better problem-solving skills than average. Especially with these disorders, you often see a lack of global problem-solving skills as a risk factor. For me, though, I just had a specific deficit in interpersonal relationships and emotional regulation.
So I couldn't figure out how to get how to regulate my emotions or not relate to people in weird, toxic ways on my own, but I was able to figure out what that meant and how to find people who could teach me. Three years of DBT basically completely changed me.