If you choose to leave, it's important to know that pwBPD can become enraged and project their lack of control onto you.
If you are married or in a domestic partnership, please read Bill Eddy's, "Splitting: Protecting Yourself While Divorcing Someone with Borderline or Narcissistic Personality Disorder."
Breaking up with a pwBPD is not a normal experience. You can expect the love/hate aspect to rear its head.
Be strong in whatever you do.
https://www.amazon.com/Splitting-Protecting-Borderline-Narcissistic-Personality/dp/1608820254