Here's some wisdom from someone who's been through it:
The fear of being hurt is often worse than the hurt itself. Rejection, abandonment, betrayal? They all cut like a knife, but driving yourself crazy trying to hide from those things can and usually will hurt you worse in the end.
It's a hard habit to break, I know.
...and another goddamn thing.
Just talk to people if you want to get to know them. There's someone out there who loves you, they just don't know it yet.