This doesnt happen to me since I have a chatty T. Lol.
Well, I do get quiet, and I have shut down, but after that, I regretted it and promised myself to change that behavior because it leads nowhere.

Crying makes me quiet, but she can deal with that.
Anything else, I opt for the talking because if I can't do it in therapy, where else can I ever try? Because I do shut down in RL, esp in my marriage, and its not a good thing.... In therapy, I am learning not to.

Hooe you can try that, too, and create the safe space you need to try getting out of the shutting down.