MKC - is there a middle ground to negotiate here? Like the t can bring it up and ask one or two questions and you can see how dangerous that feels and decide how to respond? If you respond a little, it does not mean you have to keep going.
For me, if the therapist brings it up, I can go with it some, as long as I know I can have her stop without mocking or berating me when I indicate that is all. So she will bring up something, I may deflect and we go on elsewhere and I bring it back up later in the appointment OR she brings it up, I go with it until it feels like my chest is going to explode, and then I go in another direction without worry she will try to force me back (only try - she fails at forcing me - I feel triumphant at that). My other option (when not quitting or attacking her to get her to stop) was to disassociate - which is less useful to me.