I am married to this wonderful woman for 1.5 years now.
She has severe BPD.
I am so sorry for your experience and the conundrum you face. I am reading "married to this wonderful woman" as being true feelings. Wonderful when things are going well, but, with severe BPD, things flip in an instant.
I have been married to a wonderful woman for 31 years now and have suffered similarly for all of that time. The good times are wonderful and, for the first 29 years, I was convinced I was the problem. No matter what I did, I heard how I lost control, treated her so cruelly, and so on. I remember her telling me how wonderful I was and how lucky she was to have me taking care of her. Then, 8 minutes later, I am a thoughtless bully who is controlling her. Then, 2 minutes later, she demanded I get out of the car to find another way home.
Expressing patience and gaining the ability to build a wall around yourself, remembering you are a wonderful person is critical. Strategies proposed on this site, in books, and by therapists can help, without a doubt. However, the BPD behavior always cycles back, in my relationship, at least.
I think you want to decide what you are willing to give up for this relationship. Over the years, I have given up intimacy (for 20 years now), my career, friendships, and freedom to travel. That said, the connection I feel during the good times is so wonderful, those sacrifices are nearly worth it.
However, even after all these years, I dodge fights and barbs on a daily basis. About once every two to four weeks, I slip or she mishears one of my responses and we are off.
If I spoke with my younger-self, I would say, get out as fast as possible. I have a lifetime of wonderful memories, but I also have faced a lifetime of abuse. Now, in my 60s, I feel committed to care for this person who probably cannot survive on her own. She now uses her physical ailments as a way to control my behavior and leaving, despite her manipulation, would feel like I am abandoning her. Attempts to express how her behavior impacts me sends her into anxiety fits, worsening the situation. Consequently, I internalize by pain and feeling suicidal.
Looking back, I deserve to feel loved, to be cherished and respected as the wonderful, patience, kind person I have become. I give that up to stay with my wife. This giving decision goes unnoticed by her, because I am the cause of our conflict and by others because she is the most amazing person to everyone who does not/ has not live(d) with her.
I expect you deserve the same. You may chose to stay with her because you are one of the truly generous people in the world. Please go into the future knowing you have made that choice and hold onto it when your wife asks you "How can you live with yourself?"
