You know, there is nothing wrong with you. But if I'm right, you just have a really low self-belief. You gotta trust yourself! Don't let yourself feel "I'm just me... a guy barely anybody likes/wants to hang around with".
I used to be similar situation as you're in now. My parents were over-protective as well, but they did succeed in keeping me away from smoking and snuff for instance - never even tried them.
But hey - you know how to talk. You just gotta believe in yourself, that's all. Open your mouth when you have something to be said, and don't be afraid of thinking that others will find your words silly. If they accept you to their group, they won't dislike you for it, not at all. :)
Girls aren't weird :P You're just not used to being around lots of other people, that's all. Try to get in contact with others. I know it ain't easy, but "growing up" (you know what I mean, growing up to be a more self-confident person) won't happen instantly without practising to get used to being around others either.
And I'm a guy as well :)
Not sure at all what you have gone through in your life, but it sounds like I had been in a similar situation as you - still two years ago or so. But what I simply did was to spend time in organization activities and getting to know more and more people. After hanging around with people, I didn't know from the start, for a couple of months, I realized that "hey, I'm not the shy guy I used to be anymore!".