HPD friend/depression/devaluation

Hi
So I have, or had a pretty intense friendship with a woman I met about two years ago. I'm gay, she's not, and I'll readily admit I have more tender feelings for her, even though I also have known from day one there'll never be anything in that area. But knowing that, we made for great friends, warm and loving. I think. When I met her, she was married, but in the midst of a super intense affair with a guy who may or may not be a NPD. It's still going on on and off; This is how she describes him now, but even if he's quite shady and unreliable, I don't think that's it at all. He claims to be bipolar (2 i guess)... but only got diagnosed after he saw *me having a manic episode 5 years ago. I'm bipolar 1, perfectly stable on meds, but had an episode then. I don't think he's that either. But anyway. They had or have this intense on/off relationship where they can't be good together for more than... 48 hours tops. I was amazed to learn the husband wasn't aware, since they were going at their drama in the streets of our neighborhood and god knows it was not discreet (she would physically assault him while drunk, break everything in his ex's-shop, $#%^ like that, on account of jealousy). She was always cool with me, anyway, a good friend, warm and endearing, and wouldn't put too much of her problems upon me. In the course of our friendship, I actually got clean and better (10 months now) and she was quite supportive, while she, on the other hand, has an increasing drinking and benzo problem that is getting out of hand. I played rescuer a little, and I guess this is when I got sucked in and went from being a friend with a slight crush to getting in over my head a little. The husband finally discovered the affair and called it quits, and the last months she's been unraveling. Even though it seemed there were n more obstacles for her to live with the boyfriend, the drama only increased, to the detriment of her three kids. (She would pass out/black out in front of them, stuff like that). At some point, the boyfriend started calling me in the middle of the night to come get her because of suicide threats etc. I stepped up, but also asked him to stop calling me to deal with her, which he did. Parallelly, we still had a good friendship, I was very much her confidente and a fairly stable presence in her life and her kids'. We played a little, mock-flirting, stuff like that... She always said she was extremely depressed with an anxious disorder, she has panic attacks, stuff like that. But then she's always very lively, always the seducer, the smartest dresser, extremely funny, but also overdramatic all the time. Suffice to say she just checks every item of the HPD definition... and actually I was always drawn to this type of bigger-than-life personalities. But anyway, since I got clean, felt generally good etc, I didn't think this friendship to be toxic for me, still don't, and I ve been really really worried about her for drinking more and more, and generally being so erratic around her professional life and more importantly, her kids. I wrote her a first letter about my concerns, which she loved, since there was also an important positive reinforcement streak to it, sincere too, since I was stressing how she'd always been cool with me, and deserved better than this downward spiral with the guy and the booze which was true... then. In the meantime, I saw her cold-heartedly discard another neighborhood friend or acquaintance she had, didn't make much of it cause I found the person a bit annoying too. But still. She'd sort of warned me a couple of times about how she'd just disappear from people's lives if they became intrusive (ie ghost them), always saying she wouldn't do that to me, but it did keep me on my toes. Ive been trying not to be intrusive for sure, but then it's hard when someone sends you calls for help like they're gonna die any minute if you don't rush by their side. Or just post suicidal images and messages on their ig feed stuff like that. Anyway lately she gradually started acting more and more shady around me. Cancelling plans again and again, telling me she can't see me (after offering to meet) because she has to work, and then she's just downstairs from my apartment with another friend. At some point I wrote her a second letter after witnessing her being blacked out with four small kids under her watch, which I thought really concerning, and told her how she really needs to address her drinking and everything, go to AA if necessary, etc. Also mentioned for the first time that her new habit of standing me up is taking a toll on my trust both in her and in myself. No response. And then she agreed we 'd talk, only to stand me up three more times. At that point, Id become aware of the HPD thing, and decided since I also kind of always knew how she was, I will not to get mad at her or resent her. I just let her know Id stop interfering with her life and judging her, that we were different, but I also loved her as a friend anyway. But still no response, and it seems she sort of has a new best friend now, like she needs a new audience for her drama with the on/off boyfriend... And I respect that, it's like she doesn't really have a choice. On the other hand she saw a psychiatrist who said something about her being on the bipolar spectrum - which I really really doubt, but she wanted that diagnosis because of her bf's and possibly mine, so she probably acted the part - and wanted to get her in the hospital, which she refused, but did raise my concerns again a little. If only for the safety of the kids, whom i'm pretty attached to. Not sure she's planned to discard me now, but that seems like a possibility. If only because the mirror I held for her, though still quite loving, also suggests I'm now aware of some of her more problematic behaviors (like tall tells and constant lying)... I don't want to lose her, but then if she wants to let go of me, I'll have no choice but accept it, of course. But I feel a little uneasy not knowing if she's just strategically withdrawn for a minute and will make a flamboyant comeback in a violent crisis (for instance), or devalue me viciously like she did with that other person, or what... I actually believe she's more than her PD, and is genuinely caring and even empathetic on some level, even if egocentric, but it feels like now she's totally overwhelmed by her patterns, and though with the new friend and all, she knows better than going alone at it, I still believe she's in danger. Not sure what my question is... Just not sure what to do/expect, I guess. Or if I should worry or what... Any thoughts from HPD's? Rings a bell?

It's a complicated disorder because of the emotional/mental shifts. Depends what day or hourly change in state she is in, depression or mania, devaluation or idealization, empathy or lack of. Is she in that independent phase, or dependent help me phase?

Ultimately though you just have to accept she is an adult, and responsible for her own outcome in life.