Hang in there pipefitter.
I personally want to give us rekindling a chance. I genuinely love her. I have empathy for her condition. The biggest difference between then and now is that empathy.
You know best if your heart is in the right place. Even if you decide that you're willing to give it another try, you'll want to make sure that you are properly equipped. Your plan to visit a therapist to learn sounds wise.
I'd also recommend blasting through a short book, like one of the BPD classics. The "Stop Walking on Eggshells" 2nd Edition ($10 used) is a short read that really helped me to better respond in BPD-crazy conversations and to understand how to:
(1) avoid responding so that I make matters worse, and
(2) recognize what part of a given situation is partly my own fault.
Good luck to you either way. I know it's hard.