First, don't fret overmuch about having a diagnosis or not. Many (perhaps most) members here never had an official diagnostic label to reference. Domestic court seems particularly uninterested in a diagnosis. One thought is that it expects the parents to eventually settle down into post-marriage cooperation and so doesn't want one parent painted a loser and the other a winner. So the courts focus on the behaviors. Well, mostly. During the divorce they let a lot of chaos slide by, again hoping it will wind down in time. I noticed that only really 'actionable' behaviors got any attention.
A diagnosis in itself doesn't mean as much as you may think. You would also need an evaluator to report to the court whether the diagnosis impacts the parent's parenting ability. For example, someone may be diagnosed an alcoholic. Is the person a dry alcoholic who has stopped getting drunk? Or does the person drink but only when not parenting or retreat into his room when intoxicated? Or does the person rage at the other parent and kids, even driving intoxicated with the kids? Court and evaluators will mostly ignore or minimize the first two scenarios and view only the last one as 'actionable'. Do you see why a diagnosis alone is only one factor when determining how much a person's parenting is impacted?
Sadly, I'm a bit tone deaf regarding poetry. My apologies. As david noted, that the children advocate separate homes is noteworthy. While no one should treat the concept of ending a marriage lightly, here's another reason.
Living in a calm and stable home, even if only for part of their lives, will give the children a better example of normalcy for their own future relationships. (They'll probably get married some day, wouldn't you like them to make healthy choices and not picking what they've known so far?) Staying together would mean that's the only example of home life they would have known — discord, conflict, invalidation, alienation attempts, overall craziness, etc. Over 30 years ago the book Solomon's Children - Exploding the Myths of Divorce had an interesting observation (the earliest quote I could find) 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 will enable your lives, or at least a part of your lives going forward, to be spent be in a calm, stable environment — your home, wherever that is — away from the blaming, emotional distortions, pressuring demands and manipulations, unpredictable ever-looming rages and outright chaos. And some of the flying monkeys too.
With the girls being in their teens, their wishes with whom to live the majority of time may get some weight with the court or the evaluators who make recommendations to the court. Young children don't get much of a say, but these teens are close to the time they can drive and "vote with their feet".
Since your therapist appears to be in over her head, no one would discourage you from seeking a more experienced therapist. Our BPD-impacted cases do require more than the usual form filers and hand holders. There's nothing wrong with changing to a more proactive therapist who has more strategies and confidence in what is more likely to work... .and in whom you would have more confidence.
