I tend to pull back when I feel overwhelmed or like a person is too close to me emotionally. Mostly I just shut down, get really polite, talk about superficial things, or something we've discussed before that isn't very emotional or "hot" for me. Then I calm down and move back to the emotional space we had before.

My T and I have discussed this and the analogy that worked best for me was one to how I rehab abused horses. When a horse has been abused, he (or she) often panics when tied up. So I never actually tie up a previously abused animal. I have a tree with a fork in it in my yard. I use a really long rope, take the horse to that tree and just throw the rope through the fork of the tree. When the horse gets frightened and pulls back, I let him go backwards as far as he needs to feel safe, just keeping a light hold on the rope so I don't lose the connection to the horse completely (can't let him get out on the road and get hurt). When the horse calms down, I slowly take up the slack in the rope as he moves forward to stand beside me again. As the training progresses, I push the rope down a little harder into the fork, so there's more pressure on the rope when he pulls back, but not so much he gets more frightened, or can't actually get away to a space he feels safe. Eventually, the horse realizes that I am not going to force him to stay or hurt him, and he just stands there and lets me work with him.

T says, other than the use of ropes (haha), that is exactly what he does. He stays calm and quiet and lets the client pull back, flee or whatever, but he maintains a light contact until the person calms down and is willing to do the work again.