Why isnt this something you would ask your t for help with? If i were in your shoes, i would simply present it as, "since we stopped talking about x, i have started dissociating more. I dont know exactly why. But a result is, i am unsafe when i leave here and i need your help with that."

I dont know what happens to me when my mother calls, for example - i think i still talk to my t about it, but in retrospect i see i gain weight and have a hard time. So i just present it to him as a problem WE have to solve. We are a team. Why arent you and your t a team?