the best thing to do in general, is to lean into, and remember this:
people with bpd traits are hypersensitive to perceived slights or criticisms. sometimes disagreeing with them is enough to set that off. i know that for my ex, it would, at times, infuriate her that i saw things differently, and she insisted i see it her way.
and another thing that people with bpd traits do, often, when they feel that way, is provoke others, as a means of coping. it can feel better when you get under someones skin, and make them react.
its helpful that he sees this, and he told you himself. that doesnt necessarily mean its intentional, or that hes self aware in the moment, but its something you can remember.
the best thing you can do is to not give the strong reaction you have been giving, and to change your reaction (or to not react at all). that can look like a lot of different things, depending on how the two of you relate and speak to each other. the point is not to be a doormat, but not to give him the emotional payoff hes looking for.
its helpful that he sees this, and he told you himself. that doesnt necessarily mean its intentional, or that hes self aware in the moment, but its something you can remember.
It is indeed good to remember this. He even said that he feels so threatened that he needs to defend himself with whatever he has so he hurts me, and he's not self aware in those moments like he doesn't remember I'm dear to him.
But the problem is I also can't keep all these hurtful feelings to myself. I feel like I need some space to express my anger and being upset. I know I can probably talk to him about it when he's in a good rational mood and he tries to make it up to me then, but I also know that he feels more guilty and worse about himself because of his behavior and even if I say I don't blame him at all, this doesn't change. I don't want more burden on his shoulders.
the best thing you can do is to not give the strong reaction you have been giving, and to change your reaction (or to not react at all). that can look like a lot of different things, depending on how the two of you relate and speak to each other. the point is not to be a doormat, but not to give him the emotional payoff hes looking for.
Just as dear @IWantToLive, I have the same problem too. Sometimes he even
invites me to a fight! I try to be as relax and calm as possible and not react at all, but he angrily says
why don't you defend yourself? Why do you keep quiet about whatever I say and accept it? It's not healthy! And then we'll probably be having another fight about being healthy/toxic.
How is it possible to not be a doormat and not to give the emotional payoff he wants at the same time?