Kells76,
thanks a million for your reply, makes so much sense.
I most certainly do NOT want a divorce.
Not because I could not handle it, because I have lived on my own from 25 - 38 and, as a creative person of many talents, I know how to fill my time and space quite well

I will surely survive.
What I am afraid of is how she and our 14 yo son would handle it!
My wife, asides from being uBPD, also had a quite tough life in which she became a mother by accident at 23, had a short explosive marriage with the father, and after that being basically blackmailed by her parents all of her life, never making any important decisions by herself.
So when I got to know her better, around 2-3 months in our relationship, I've came to realise that the most important thing for her is to start making her own decisions, even if wrong ones, because she needs to grow and to learn by mistake. So I enabled her to do so, even if at my expense and with great sacrifices.
Off course, it took 10ish years until I've realised that her erratic behaviour matches highly-functioning BPD traits almost totally, except for suicidal thoughts and attempts, which I think are not a part of her version of BPD because she is totally scared of death and nothingness, and that fear makes it (I hope) impossible for her to even contemplate suicide. But, she auto-destructs in milion other ways constantly.
In that respect, I think I am really her best shot at having a most normal life she can have.
But the thing is that she completely positively answers to the most important question of any relationship, as I see it: Does that person make you a better man? And she really does. I can hardly recognize myself after 17 years with her! All the stuff I hated about me is gone, shattered, as any of it could not survive a week with her. I was up in the air, know-it-all I-am-the-best-fck-the-rest kind of guy, always surrounded by people that praised my talents and virtually saw a semi-god in me in a way. She gave me reality, gave me my true self as I was before becoming corrupted by fame and being idolised by fans (I had a very succesful music project in late 90s early 20s).
2ndly, our son is for both of us the best thing that ever happened to us, and we invested most of our lives together into his upbrining, trying to raise him well while preserving his beautiful playful soul, finding a nice balance between rules and freedom. He is everything to me, and I think he would be shaterred by our divorce.
Also, it is really unclear what would his choice be if we divorce, and here in Croatia, where we live, kids after the age of 14 have a right to express their desire of a man care provider in case of divorce.
I have a really close bond with him, as I spend much more time with him then my wife, but as a really good mother but also a special education teacher whose father is a doctor, she is incredible in providing care so she is the one handling all of his health and other issues that occure, so perhaps he might feel safer staying with her. Also, though I earn 5x as much as her, she has a steady pay check each month, and my income is erratic, and although in the end each year in total is getting better and better and is now close to six figures in $ (for Croatia, solid upper middle class earnings), there are months where I get only a bit more money than my wife, and then, off course, there are huge discussions about money, because at those months my wife basically must give all of her salary just for the our last month credit card expense.
S no, I don't want to divorce her. But, I also surely don't want a "tough" divorce where we would fight and become enemies. I must stay a gentleman and a nice guy at all cost, never exposing her as a person with mental problems, because that would surely make her break every bond with me, which would completely ruin my son's life.
So if she persits in having a divorce, I will have to play her way.
Right now I am really not sure what is going on, as I have had situations like this and each one of them was resolved or dissolved next day when her head "clears out". But it's always a lottery in my head.
If I see tomorrow that she is still "on the other side", I somehow must tell her that I hope that she is not about to make a decision, like so many times, that she will later forget and be sorry for. But it can not sound like a threat. It must sound like a genuine call for reason, stopping her from an auto-destructive move.
But one thing is bugging me - how are highly functioning uBPD people on their own, if they live alone? She is now 50 and her BPD is, I think, much better, and she controls her outbursts much better than before.
Would she perhaps really be more happy alone, in her own, small, tidy apartment? Without us dirty loud annoying guys around? Would that perhaps be a better life for her? Can they have episodes if they are alone?
Am I selfishly stopping her in going that direction?
Cause this is what she often states when having an episode, that she would be most happy living on her own like that. Perhaps even without our son, only with a dog.