The only reason some people maintain those friendships is because of JWs who don't tow the party line as faithfully or should I say as fanatically as others do. I didn't maintain friends either, but it doesn't have anything to do with how nice you are. I think once you figure out how to make friends outside of the organization you will realize what real friends are. Not that all of them are, by any means, but real friends will stick by you in the tough times, thats how you know.
I'll tell you one thing, from being in a family where we weren't considered "strong" enough witnesses so that I didn't get to associate with the kids my age inside, and a fanatical mother who made damn sure we never said two words to anyone outside, I can tell you I'm a bit socially retarded. Sorry, its the only word that fits. But even so, I have managed to make some good friends outside.
Sometimes therapy helps you get past the distrust. But you really have to let go of your fear that all people outside are evil. Actually what you come to find out is that it's about the same percentage as the ones inside (who are evil).
Good luck!
Ada