It gradually became easier for me to put myself out there once I finally figured out that most people who act cocky actually aren't deep down - they're just overcompensating to cover up fears. In most cases, it's been that way since they were very young and they became that way due to regular, routine bullying they received - often from their own family. Since it's been so long, it's instinctive at this point, and the real reasons for why they act the way they do are long forgotten or mentally buried so they don't have to face them.

I've actually wound up still not being terribly social for a different reason: I don't trust people until I really get to know them well, and - due to some subtle body language cues I know to look for - online relationships aren't really something I personally feel I can ever really trust. It's like I've swung to the opposite extreme for the reason behind my not socializing - I'm more confident in myself than others, although I try not to be an ass about it like so many others. It's kind of a weird combo of confidence and distrust.

My point in saying all this is that a majority of other people are no less insecure than you are - they just deal with it in different ways. The fact there's relative anonymity in online interactions allows their worst instincts to be unleashed because there's little chance of it coming back to bite them in any significant way. It's their opportunity to return bullying they've received without fear of any significant punishment, so they take full advantage of it just to feel strong/superior for the fleeting moment or two that it lasts. They keep doing it because it's like a natural drug addiction - they get briefly high from it, and want more.

Learn to recognize/understand what's really likely motivating those yahoos bullying you, and it gradually becomes easier to blow those people who bully you off for being the overcompensating jerks they have become. They're not worth your mental energy getting upset over because they're the ones choosing to do things that are wrong, not you. Decent people are open-minded, and try to discuss differences in a fair manner - so those that don't aren't decent, and aren't worth the respect they're not giving.

Congrats on overcoming your personal fears - that can be extremely difficult because we talk ourselves down into holes that we don't deserve to be in since we are our own worst critics. Do it long enough (which we all do), and it becomes an automatic way of thinking. In theory you can take advantage of this effect to also improve your self-image by making an effort to talk yourself up. I've read it takes around 40 days to make something become automatic enough to become a habit. I don't know if that works with psyching yourself up, but maybe it's worth a try.

Anyway, good luck with your new potential friends, and remember that there are millions upon millions more of us out there if it doesn't. Just keep plugging away at it until you find people who get you - we're all in our own little bubbles out here, and it's nice when we can make them a little bit bigger to include someone else in them.