Hello, I’m new to this subreddit and I do not personally have BPD but I’ve been very interested in personality disorders as of late. To be clear: **I’m not requesting a diagnosis, I’m more asking about how I can help someone who may have BPD (or even someone who doesn’t but parallels some symptoms of BPD) but hasn’t officially been diagnosed.** I started doing a lot of research into BPD, and everything sort of clicked.
Just to preface: I was this guy’s FP for a good amount of time so I do know a LOT about him and how his brain works. I also would not suggest a diagnosis on ANYONE if I wasn’t absolutely swimming in evidence. That being said, I can say with 95% confidence that if he went to any psychiatrist about concerns of having BPD, he would get a diagnosis. There’s nothing inherently wrong with that, of course, but his untreated heightened emotions have been a huge source of my personal pain for almost a full year. I have really exhausted every effort as a non-professional and as a friend to love and try to help him through what he goes through, because I really truly care about him.
Things went south when we started dating. It’s not necessary to get into the details, but essentially, what seemed like minuscule or non-issues to me and the people around me were enough to unravel him. I’m genuinely so sorry for any pain I caused him whether I meant it or not (I didn’t.) We attempted to be friends afterwards.
This summer, I was hit out of the blue with a complete flip of the script, and he decided that I was a horrible person and I’m still really really fuzzy on why he came to that....I want to reiterate that if I genuinely fucked up in any way, I would 100% own up to it and do everything to try to make up for it....but it really truly wasn’t about anything. He then took all of m friends away from me by giving them “me or her” ultimatums, including my two closest friends in the world at the time, THEN did everything he could to hurt me and my reputation, all of this happening when we were literally playing love interests in a play.
I see him occasionally but not really that often, and it’s been 4 months but the wrath will not stop. He is still fuming about me to my friends and yesterday he posted something about me that was so unnecessarily mean that I don’t know what to do with myself.
I want him to get the help he needs. He deserves to be happy and I’ve always believed that he has the capacity to be a good friend, but he’s untreated and so jaded and angry right now that he’s acting straight up evil. And I want this harassment to stop. He knows exactly what will hurt another person and deliberately uses it against him. I’ve done nothing but love and care for him, and since the summer time, all I’ve done is leave him the fuck alone. It will not stop. Ive tried confrontation, I’ve tried ignoring it, and I’m really close to going to admin at my theatre company about the harassment but I want to make sure I’ve done everything I can to diffuse before I do anything like that

TLDR; I have good reason to believe someone who used to be my life has undiagnosed/untreated BPD and I need advice on how to go about getting him the help he needs in order to get into a better headspace, and also on how to handle his inappropriately malicious behavior toward me.