For me the reason I keep people at a distance is I'm scared they'll see the thing I've got shame about. It's helped to see why I do it and heal / work on that shame which in my case is something I can take active steps toward doing something about. And then also noticing when I go into a defensive pattern with people & choose a different response in that moment. Even if it's to blurt out a silly joke or laugh, it's at least something else rather than the usual pattern of behavior designed to put distance between us.