My ex husband had BPD and I never knew what version of him I was going to get each hour of every day. It was exhausting. I loved him as he is to the core a good man, but has his challenges so I can see why you are wanting to see if there is a solution. I am afraid that its a personal journey for everyone and what you are prepared to sacrifice to stay on in your marriage.
Its not easy to live with and honestly it destroys you in the end.
The abuse that comes with it is horrendous and not fair on the DC.
I left with police escort one morning. Prior to that morning I had lived over 7 years being terrorised by my ex, thinking the whole time I could fix it, mend it, behave differently, say other things to calm him down, and turned into a shell.
The amount of times I tried to defuse and steer him from threatening to kill himself when I would say I was leaving, it destroyed my self worth. His threats were just that, and he is well and truly intact. He was fine while I had to pick myself off the floor with years of therapy and I wish him the very best. He is still a good man, just a terrible partner material.
So no, there is no magic solution in fixing things, you are not responsible for your partner, he is. Regardless of any diagnosis, only he can and you have to decide what your can tolerate.