She has some medical issues as well that cause her pain which she has been dealing with for the last six years - it increasingly looks like these conditions have more to do with her BPD than any corroborate. There is a large pharmacy of medications for it in my closet however.
Been there, seen that. My ex insisted she had lupus, then fibromyalgia. In years past, Bipolar was a common diagnosis, it had symptoms similar to BPD, because back then Borderline often wasn't covered by insurance. Bipolar is largely a chemical imbalance and drugs are helpful, whereas BPD is a cognitive and behavioral disorder. While drugs may
moderate the symptoms, the real treatment is
long term meaningful therapy. That is typically DBT or CBT... Dialectical or Cognitive Behavioral Therapy.
The minute my wife and I were to separate, I would be reassigned somewhere far away.
Have you investigated that? What if family court granted you equal or substantive parenting time, even if only in the temp order? In our sort of obstructed cases, unwinding a marriage or settling custody and parenting schedules take much longer than normal. (My divorce took about two years, it was a "temp" order the entire time until the final decree.) So until you investigate how it all will be handled by your employers or contract, you may not be considered "single" during the legal process.
My question is whether I should stay. I have stayed previously largely for the children. I am becoming increasingly overwhelmed. I'm not sure how much more of this I can take, even if I still think it is the wrong decision.
Back in the 80s there was a book written about the then-popular view
Tenders Years Doctrine that mothers were always the better parents. While your employment situation is a factor, here's what it said:
A few decades ago the book Solomon's Children - Exploding the Myths of Divorce had an interesting observation on page 195 by one participant, As the saying goes, "I'd rather come from a broken home than live in one." Ponder that. Taking action, as appropriate, will enable your lives or at least a part of your lives to be spent be in a calm, stable environment - your home, wherever that may be - away from the blaming, emotional distortions, pressuring demands and manipulations, unpredictable ever-looming rages and outright chaos.
In short, you can choose to make the best of a lousy situation, whether you stay with demonstrated improvement, "stay for now" pending improvement or whether you go. The reasonable best.
Your decisions of course will be affected by your spouse's actions and behaviors. But it's always up to you to decide what boundaries you will set in your life, what you will do or not do, etc.