Couples therapy with BPD wife? Is it a waste of time?

I have been living in hell for almost 4 years now. My wife has been extremely abusive, mostly emotionally. Once she admitted she needed to get “back to therapy”, she implied that she knew she had an issue, but refused discussing it. She never did, just found excuses to not go. I started insisting that we needed therapy together regardless, she refused, and would rage about it because she wasn’t going to be “labeled” by anyone. I worked very hard on improving my communication, and blamed myself for all our failures. She started to dismiss all my calm communication attempts: “Why can’t you be a man?”, and it worked many times, but others I was able to keep my cool. She started her own therapy finally. But then she also started to rage in the middle of the night more often, waking me up, sometimes even physically attacking me. This was so disorienting I couldn’t keep my communication clear, and I would explode too, or just sponge up the abuse. I started having panic attacks because I knew she could attack at any time, and I couldn’t be safe, no matter how much I tried. Eventually, I did the “therapy or we split” and she agreed to go.

Therapy made everything worse. I wrote about it here. She would dominate the therapy (she is also a psychologist), and would flat-out deny her abuse. She would rage preemptively to intimidate me, and if I brought up the topic in therapy, she would rage after. She would also rage more at night because she knew that it was harder for me to control myself then. Everyone in that reddit post told me to just leave her, but I can’t, because we have a son together, and I worried that she would abuse him in the future. I started to make plans to leave regardless, and try to figure out the custody laws. I also cancelled therapy.

We have talked a few times heart-to-heart, some other times she has raged for no good reason. She admitted she dissociates when she rages. This explained a lot, and got me thinking about some psychological issue. She started reading the book I gave her about abusive relationships, and promised she would organize her thoughts to address ‘that’ (she gets “stuck” when she has to admit she has abused me). She said we could go to another therapist to work with ‘that’.

I have now realized that she has BPD. Everything makes sense now. The confusion, the insane accusations, even her difficulty finding a therapist. She has admitted to 6 of the 9 criteria for BPD (and I suspect a 7th one) using language very similar to the DSM criteria. I think that she knows she has BPD to some extend (but she might refuse the diagnosis). The little she has mentioned about her therapy suggests she is working on some BPD things.

This puts me in a very strange position. I know she has BPD, and I know she knows she has BPD (to some level). But I know that it is a terrible idea to bring this up, I’ve read many disastrous stories here.

She wants to go to couples therapy, but I worry it will be a repeat of the previous round. I’m going to ask the therapist for “individual assessments”. My main goal for this therapy is first, to stop her abuse. It has broken me and hurt me too much. She does it in front of our son, and this worries me much too. Second, to give us healthy ways to communicates both of our needs. Right now when she needs something, she just gets angry at me and rages about something irrational and unrelated. When I understand what is the real thing she wants, it is always very easy for me to fulfill it, the issue is never that we disagree. Also, I have no way to express my needs to her. Anytime I do, she takes it as an attack, and rages. I have asked her in our heart-to-hearts how can I bring up my needs to her such that she doesn't explode, and she admitted that there was no way.

I worry very much about the couples therapist because we had a terrible experience already, the abuse just become worse. Should I say to the couples therapist that I suspect she has BPD? If not, I should at least bring up the specific behaviors and things she has said to me. Or what can I do to make this round of therapy productive (my 50%)? Or is this just a bad idea, since last time it just made things worse?

TL;DR Previous couples therapy failed. Now I realize wife is BPD. What can I do on my 50% to make therapy worthwhile that I didn't do before?