Wow, there are some loooong posts in there - I'll admit I did not read through all of them. I too was extremely shy and had low self-confidence in social situations while growing up. This was mostly because I had worse acne than most kids, but the result was the same.
But when I was in 10th grade I switched schools, and I noticed something when I found myself in that new environment. Confidence is all mental (obviously). Ever see a goofy looking guy with a beautiful girl? Its all in how you present yourself . . . personality is part of it, and as long as you are a nice and interesting guy people will probably like you.
It also has a lot to do with the appearance of confidence. If you act confidently, others will see you as confident and automatically have a certain level of respect for you. Relax (I saw this was mentioned) - don't stress about little things if this is one of your problems. Open up and be available to conversation, even if its just a comment or two at first. And you will also have to adjust to initiating conversations. This can be a tough one, but remember that if you appear to be self assured, people will see it.
Just my 2 cents . . . Good luck Terinox!