I would work on things slowly; how about when you get your hair cut? Maybe let them wash it? That helped me, having my head back and getting shampooed and rinsed a couple times before getting my cut. But even if you don't want to get it shampooed, I'd make an appointment to get it cut and/or show up every few weeks until you get use to that then try something else.

Sometimes it's a little easier if you start with you touching someone else. Find a "crowd" and work your way to the front, lightly touching people's shoulder and saying "Excuse me". Let a good friend have your arm and just massage that (and return the favor). Pretend your back itches and let someone give you a back-scratch.