Hello Vet06,
Really glad you found us. Really positive that you working with a psychologist on setting boundaries to protect yourself from your wife's dysregulated behaviour.

Living with all aspects of BPD can be very difficult and emotionally overwhelming. Sounds like you have been together for a while.
As you have found your w will rail against your boundaries and in the short term her dysregulated behaviours will increase. I see Lifewriter16 has given you a link on Extinction bursts which will explain in detail what is happening.
Here on this board with support, advice and coaching from many members who can share your experience it is possible to improve things for you. My life and my relationship has improved and my h's behaviour for the most part is stable, but it took a while to get to this point. Coming here helped me focus on looking after myself and increased my understand about this illness.
We look forward to hearing more from you, let us know how you are getting on.