First, welcome to our big family!

Please thank your friend for her invaluable book suggestion.
You can't learn everything at once of course. There is an immense quantity of information, education, enlightenment and strategies, so much it will take you weeks and months to absorb what is helpful in your situation. But never fear, our interaction will be both helpful and refreshing. We've been there, done that. Learn what worked for us and surely some of it will help you.
We do encourage counseling, including yourself. Sadly, most who are acting-out disordered seem to resist therapy, the Denial is that intense. The children are in formative years. Experienced counselors can surely help them in addition to anything you share with them.
Last I heard, minors can't have accounts or post here but there's nothing to stop them from looking over your shoulder.
It's true that most PD relationships discussed here never did get an official diagnostic label. Many professionals are reluctant to pin a diagnosis on someone, especially not if they haven't been directly assessed.
So what we do here is to follow the process family courts use when cases come before them... they use the
documented behaviors to construct temporary orders, then later regular orders. In my own local court, all the professionals studiously avoided commenting on either spouse's mental state, they just set orders in place to limit poor behaviors. We don't have the authority which courts have to issue orders, so we call them
Boundaries. <-- Click to jump to our Tools and Skills workshop board so you can read articles describing how we design and implement practical boundaries.