I have used some of comrademoomoo's techniques of naming what I want to do rather than doing it. It helps me from getting stuck and shutting down. I don't usually become sarcastic or mean. I just shut down and don't talk. I close off and push her out. I think the times that I am able to name it, she's been able to help me talk about it and work through whatever. I'm not able to do that all the time or even half the time.
It has taken practice and seeing that my T is helpful and doesn't take it personal.

Maybe even in that sarcastic way, you could say that you are feeling the need to be sarcastic, uncooperative or whatever.

I've even used the phrasing that anger has joined us or something similar.

My T has helped by accepting whatever I am feeling, welcoming those feelings, not taking it personal, helping me to continue to stay connected to her and talking. Sometimes that even includes me saying that 'I don't want to be here' meaning that I don't want to be in the emotional place/with this topic and her picking it up and moving the discussion to something completely off the wall.