Hi Zoogman ,
I have read a lot of books on BPD, and I can tell you none of them has a solution. All they can help with is to not feed into the drama. Another way of looking at the problem is by understanding the EOS theory:
https://psycnet.apa.org/buy/2010-06891-012What this study tells you is that by doing extreme actions such as self-harm, the pwBPD can stimulate their own EOS without interacting with anyone else. However, by interacting with someone else, it's much easier to cause this stimulation of the EOS, especially if that's an intimate partner. And they are always unaware of why they are doing that.
When things get bad enough, the only solution for the intimate partner is to live apart. That's exactly what has solved the problem for me. My wife still does lots of drama through text messages but those don't bother me as much as the screams, throwing of objects, etc.
The only thing that can possibly be a solution is treatment with a specialist, preferably through DBT. But they will usually not want to do treatment to change their behaviors or thoughts, because for them, it is already working for them. They don't understand that their intimate partner feels drained and exhausted, because for them it goes the other way around, exiting the EOS (and other circuits as well).
However, in the event that the pwBPD "hits a wall," then they may finally try to heal. I mean something very tough, such as the threat of losing child custody along with a divorce. My wife hasn't started DBT yet, so I'm afraid that living apart hasn't been enough of a hit for her, but I'll be patient and giver her more time.