Hello livingdeadgirl, I am sorry to hear of your turmoil. You have a degree of self awareness and have described a number of traits for BPD in yourself but you would be best to speak to a T about this.
Misdiagnosis of BPD is relatively common as depression or bipolar disorder. Again, I would encourage you to speak with a doctor about your thoughts.
I'm glad you're not drinking if that is making your circumstances worse.
There is no specific medication for BPD but some types of medication can help with certain symptoms. It's best to speak to a doctor about your lack of improvement and disappointment with your progress.
Your boyfriend may have developed some healthy boundaries around what you describe as threatening/manipulative/mean behaviour. There is not much you can do other than seek further help or try something different in order to either minimise or cope with the feelings that lead to these negative or hurtful behaviours.
Treat your boyfriend with respect and gratitude next time you speak. Try to keep it that way.