I knew someone with it and he had it really really bad. It was my old roommate so I really couldn't get away from him and he was really awful to me. I helped him a lot but he was so insecure that he didn't like accepting help and he was EXTREMELY obsessed with me that he would push away other people from me just so he could have me all to himself because he was incredibly jealous and was always paranoid someone would take me from him. He would also always pretend we were dating and it was just creepy. I don't have any communication with him anymore but I hope he gets help since this has apparently been happening since he was 14 at least and now that he's 19 it's really bad. I think he has other personality disorders though and not just BPD. He had a lot of issues.
I hope you're doing ok though and you don't let it control your life like this person I knew.
