Welcome to BPDFamily, happy to meet you, sorry you're here...
I don't have all the answers, but a few things to keep in mind
Firstly you're going to need to separate these out in your mind - not just for the sake of the list, but compartmentalizing so you are able to handle the tremendous amount of factors you'll be juggling in the future. Otto Kernberg is a really boring but surprisingly helpful read, one of the "early" researchers into BPD before it became du jour.
-His insults and your ability to be hurt by them; this is much more difficult for parents than spouses to become immune to the truly absurd insults. A particular BPD has labeled me with so many bizarre and contradictory terms that it really doesn't affect my self-esteem/schema...and that sounds like one of your major issues right now.
-Enforcing rules is a separate issue, don't tangle them together. This one might be one of the easier ones to solve since it's less likely to be psychopathology-driven than some of his other behaviors.
-Getting him into therapy - my only hint here would be to not let him associate "therapy" with "Mom's idea and she's always asking me about it and how it's going and what I'm learning"...you'll need to back off and give him some space to quietly make progress without feeling like you're boasting. If he's BPD, he suffers from crippling shame and insecurity...and mothers can make that much worse just by being moms.
-He believes you are a horrible mother who is causing problems for him. We're all imperfect, so he's probably drastically over-stating it but has a kernel of truth. Look at yourself and resolve to find at least one area where he's actually right (and not some weird "He's right, I'm too soft on him" way).
Finally, is he your only/oldest child? I just ask because it sounds like some of his behaviors are not necessarily tied into his BPD and are just "normal" teenaged angst - it might be more commonly directed at parents who did fail their children in a meaningful way, but it can hit any family. That's actually "good news" (
okay we have a crappy definition of "good" around here...) because it means you needn't resolve yourself to never seeing him again - he may well just "hate you" from now until he's 19, or 22, or 25. I'm of those who believe boys/men do not change much after the age of 25 - but until then you've got a pretty decent chance of salvaging his relationship with you...it won't likely be next week or next month, but hopefully you are able to play the long-game here