>>4
People with shitty self-esteem are often quiet/shy, because they afraid of how you're going to judge them. It's not really voluntary. They might come off as being difficult, boring and even a slightly snobbish, but inside they're actually a mess about what they should say or do next. I've been there, done that.
>>11
It's meant to be pretty hot. I had streaks in my hair re-done recently and I forgot how much it burned. But yeah, point is, you didn't have to confront them about the issue. I would've queried them at the very least if I was worried. ie: "Say, is it meant to be this hot?" After hearing this, I think you just need more life experience OP. Getting a job is a great step, because you learn how to deal with people and you meet new people everyday.
Try different things all the time. Don't stick to your routine lunch/outing/weekends. Becoming more knowledgeable in a variety of things makes you a more interesting person, and consequently, have more things to talk about. Even little things like trying different eateries when you're having lunch/dinner will help you. Then the next time you eat out with friends, you can be the one to "know a little place with a great menu".
Improving your physical appearance is also a great confidence booster. Kudos to the haircut. If you think you look good, then you will care less of what other people think of you.
Don't expect much when you just pack up camp and leave without telling anyone. People that you didn't tell will think that you thought they weren't important enough to you. Friendship is a mutual contribution believe it or not.
Online friendships are cool. The problem is when you have more online friends than "real-life" friends. If you really want to break out of this social awkwardness, I would recommend you to allocate less time online. Ultimately, a real hug beats a cyber hug any day.
The most important thing is to never retreat back into your shell. When you're hovering outside that door, wondering whether you should step in or not, always remind yourself that it's "now or never". You have many reasons to change. No excuses for putting it off.
Lastly, remember that most people have little patience to crack open the shell of a shy person. To them, it is frustrating to continually start conversations only to have them met with one word answers. Believe it or not, it makes them feel a little rejected. The least you can do is smile and laugh. And greet them when you walk past.
Goodluck OP.