I'm kind of like that too.
But not proud of it. I wish I could be more extroverted. The funny thing is I do tech support and talk to strangers on the phone all day like it's nothing (and I'm pretty charming), but on the street it's a completely different story. I overthink everything and tire myself out. :/
you know whats crazy, i never really notice these traits in strangers, you always think your the only one, but in reality a lot of these ppl are thinking these same thing.