I found that "retreating" doesn't work too well for me because you can only pull in so far and the complications with pulling in and making the "space" smaller don't give much room to maneuver :-) So I finally decided to work my way out and give myself more space, work on my fears and things I didn't like in the outside world so I could make plenty of space around me. 30 years ago I use to think of myself as being in a cities with "levels" and walls around each level and I'd pull back a level when the walls of the previous one were breached. I got inside my head, the "center" and then, where was there to go? So I started clearing out the city and wandering outside my walls to the plain surrounding the city. I began to understand that I have really good defenses and can keep myself "safe" can raise the drawbridge, drop the portcullis and cue the alligators in the moat and men with hot oil on the ramparts before the other person or situation I don't like or am afraid of can blink so I started "staying" longer and longer before deciding I couldn't stand something and/or it was too dangerous. Eventually I could go in and out at my pleasure without feeling bad things were going to happen.

You have to be able to let people "in" and go "out" of yourself. I decided when I started therapy that the one rule/image I had was that I was a minesweep or ice breaker who had to keep the "shipping" lanes open. I had to "talk" to my therapist no matter how scared I felt and had to let her "in" to what I was thinking and feeling no matter how scary that was. I had to let her in and I had to go out, the "fetal" position wasn't allowed no matter what/no matter the pain. I had to keep communicating.