If you notice I do not mention any curiosity or interest about his needs. This is intentional as I am trying to exercise putting myself first.
I did! It's great to hear that you're making a conscious decision to do that. Good on you!

Yes it is difficult to understand and there are probably numerous explanations that we could extract from the DSM5, however just from my own experience I'd categorise it under the push/pull behaviour. Also my ex was open and honest when calm about his behaviour when dysregulated and he admitted that sometimes he just wanted me to hurt like he did. Which when you contrast to a young child lashing out when they are upset, is not dissimilar. A pwBPD has limited emotional maturity and this is just one of the ways that I found it presented itself in my r/s.
How else are you prioritising yourself in the rest of your life? Are you making positive changes elsewhere?
Love and light x