I'm sorry to hear of your latest altercation but it's good news that you had the awareness to exit and let her face her consequences. Many here, myself included, found it hard to overcome our natural urges to stick it out and keep trying. When it gets that bad, so bad even you realize it's unhealthy to stay but you still stay, then you do need objective help. Do you have DV resources helping you or a counselor?
Getting a counselor to help you view your life objectively is crucial. You're looking from the inside out and it hasn't worked for decades.
However, not to be discounted is the peer support here. We can help you get and stay objective. We've been there, done that. Feel free to tap our immense collective wisdom. We are pretty good at identifying what tactics and strategies are likely to work and which ones aren't.
You may think the police and associated agencies will help. And they will. At first. But two problems... .(1) They're used to defaulting to help the woman since that's the PC thing to do, after all, everyone says they victims have to be the women. So the longer you stick with her the more likely she will come out on top. (2) The police and court-associated officials may lose interest in "going the extra mile" to help you if they don't see you helping yourself. What I mean is that if they see you always returning right back to living with your aggressive spouse, then they'll eventually give up on you. They'll think, "Why bother separating the two, getting it handled in court, if they get right back together again and start the abuse cycle all over again?" They won't see you identifying the problem and stopping the
Wash-Rinse-Repeat cycle endlessly. They'll conclude you're using the police and other agencies for revolving-door solutions that get you nowhere so why bother?
She won't change, not after decades. So it's up to YOU to change. That's precisely why you need a very experienced counselor. You may have overwhelming co-dependent traits. That doesn't mean you're the cause of the conflict, it just means that you and your spouse are unhealthily feeding off each other's deeply ingrained issues. Good that you came here, you'll hear honesty, practical suggestions, wise strategies, needed education and more. The more you learn and apply, the more
informed and more
confident your decisions will be.

This time she went to jail. Just a punch in the face, but I left the scene to prevent further escalation. She does not remember the sequence as I do, starting with her throwing the first punch after a small incident with a cat.
Be careful here. Many here have reported that their ex's story didn't match reality. Really, knowing her as you do, would you expect her to actually agree to an account that placed her At Fault and To Blame? Never! That's why BPD has been called a Blamer's Disorder, it's never their fault, it's always Blame-Shifted to someone else, usually us! So don't agree to her rewriting history to make herself look less bad. The down side to that is you'll be the one looking more bad.
That might be a good Boundary. Never agree to change history to let the other avoid consequences or salvage their Public Face.
And that comment about being isolated from friends is also a known tactic. Remember the old saying, Divide and Conquer? That's another method how a person with BPD (pwBPD) manages to get their way so often.