bpd, you may have started the firestorm but I may be about to throw gas on it.

I have been thinking much the same things as what bpd has said. I am not a T and I am not BPD. I have many friends who are T's and friends who are BPD. This again does not make me an expert by any means, just someone who has seen both sides.

BPD needs to be diagnosed by a psychologist who is trained in doing evaluations.

Therapy needs to start with skills, CBT or DBT.

Seeing someone with BPD 3 times a week especially before they have done any CBT or DBT is creating dependance which is not healthy, it feels good now but will hurt more later.

I do believe that a good LCSW can do CBT and/or DBT.

This T is bringing out issues that need to be worked on and it sounds like she is both willing and able to talk with you as you move through them. That is very good. And having a relationship with this T that is safe enough for these things to emerge is also good. But it feels like she is putting the horse before the cart.
Working through the "mom" stuff is essential but it is a b* and by the sounds of things the work is begining without a "tool box" as my T called it. Yes, a T will be much better able to manage the storm. Knowing that someone can weather the storm is very healing but it does not create change outside the theraputic environment. You are not getting the valuable opportunity to practice your CBT skills. When storms come up outside of therapy without both having and having successfully used your CBT skills you are more likely to continue to rely on old patterns.
I don't think you need to fire your T but I do believe that the treatment plan needs to be re-evaluated.