Somehow a conversation (one of hundreds the past several years) trying to help my PWBPD issue turned into a chance to comment on my failures. I made the mistake of speaking honestly about how I felt and my SO took it as me blaming them for everything wrong in my life and then went on to attack me for the failures and talking about how awful I was for even including them in any comment about them.
I realized too late, as I sometimes do that I made the fatal mistake of being open and honest, something my BWBPD can do anytime they want, but I can only do if it is about something or someone they don’t care about or share identical feelings about.
So I’m painted black and sitting here thinking about all the hours I’ve bent over backward doing things for them that are apparently my duties as a partner but realizing I’m allowed to have no expectations.
I’m supposed to be what they need when they need it. My existence is secondary.
And feeling incredibly alone, that hurts.
Sounds like you're arriving at that point in the road where there's no more hope of change or normalcy, and you need to decide how you'll handle this going forward.
Is your PWBPD diagnosed? It sounds like you've been aware of the fact that they had a BD for a while, but just now coming to grips with the fact that behavioral disorders are very real and very unlikely to change.
For me, I sort of came upon it the opposite way, where I had tried MC with my then-wife twice, and had tried to accommodate her requests and demands, only to be met with more demands, which were often inconsistent with what she claimed was what initially upset her. I was really perplexed, because all the advice I read about being a good partner, and resolving conflicts within a marriage, when followed just lead me in circles. It seemed like she was hell bent on creating conflict for its own sake, and yet when I read about things, went to counseling with her, and eventually counseling for myself, the answers I would receive were unhelpfully along the lines of "No, people don't just act like that, you must not be really listening to her."
Learning about BPD - whether or not that's what she was, or some combination of BPD, NPD, and ASPD - helped me make sense of the situation for the first time. I had already more or less accepted the situation was hopeless, and now I could understand why.
I think for you, some radical acceptance could help you see the path forward, namely accepting that this is what your partner is like, and this is how they will always behave. Knowing that, what do you plan to do about it? Consider your options, and the paths forward with each.
For me, taking some actions, even if the went nowhere in the short term, helped me deal with the hopelessness of the situation. In my case, I decided to end it, but it was hard because we had a kid together, and owned a home that she could not afford to keep on her own. Just planning and thinking of how to unwind all this and separate successfully provided a mental escape and relief for me. As did some of the steps I took: getting my own checking account for emergency funds, getting a storage unit to start moving personal belongings into, etc.