Hi Stopeggshells,
I can relate with your post, it's a frustrating experience when what was stated by our pwBPD changes on us and we're blamed for everything that is not going right in the r/s. I tried to correct my exuBPDw so many times and I was left confused, frustrated and depressed that nothing was changing in the r/s. You've been at this for a long with 6 years.
JADE was a life saver for me, it's one of the best tools to use, JADE stands for Justify, Argue, Defend and Explain and it's what you don't want to do with a pwBPD. It helps to look at it from a different angle as well, reality really is open to debate, how one person interprets something can be slightly to very different to someone else. For example, let's say that you have several people that are witnesses to an accident and they give their statement to the police, what they repeat back should be different from one person to the next because we all interpret things differently than each other.
To a pwBPD feelings = facts, so what the person feels has to be based on facts to them. A pwBPD is just wired a little bit differently. If my ex uBPDw believes that the sky is red, now that I know to not JADE, so be it, it doesn't change how I interpret reality because I know that the sky is blue so I won't try to explain that fact to her because it will give her an opportunity to create conflict, I want to make myself a small target and not give her chances to pick a fight.
Don't "JADE" (justify, argue, defend, explain)