I don't understand him trying to convince you to trust him. I don't have nearly the trauma background that you do, but overcoming childhood stuff for me has involved trying to hear my own voice and trust my own instincts. My T is consistently very warm and kind, and I still get the urge to run the other way sometimes. Instead of telling me to trust her, she waits, sits patiently, gives me a chance to doubt her, lets me run away and then come back if I need to. Over and over. Lots of flexibility and empathy and encouragement but never pressure. It's 99% show and 1% tell.

I also can't imagine my T ending the relationship over some kind of messiness that happens between us. I have said some things to my T that would probably cause your T to lose his mind (including calling her smug and implying she is a bad parent), and she's still right there. Deep healing demands deep trust with somebody who can demonstrate that they are worthy of trust and who is confident that they can use your trust in the service of your own improvement.

I don't think your hesitation here is a CPTSD overreaction, but even if it is, you deserve to be in a safe space where you can take apart that reaction and see which parts serve to keep you safe in your present life and which parts of the reaction you can start to set aside.