I used to go through the same thinking pattern. I was bullied relentlessly throughout school, and it made me think very poorly of myself, and I assumed everyone thought the same of me.

It wasn't until this past year I was finally able to get over it, and push those thoughts aside. I came to the realization that we spend 99.9% of our time in the blind spots in other people's thoughts. How many faces do you see when you go to the store? How many of them do you remember the next day? When you see someone and a judgemental thought crosses your mind ("What an awful haircut that girl has."), do you obsess about her bad haircut for weeks, or is it a fleeting thought?

When you realize no one cares, because they're too busy thinking about their own stuff, it's like a weight being lifted. I lived with agoraphobia for years, and that simple realization was all it took for me to go out and not worry about what other people think, and to just go out and do things. Even if I make a complete fool of myself, are people really going to obsess over what I did every minute of every day for the next 5 years? Nope. They probably won't even notice, or still be thinking about the thing that made me uncomfortable & embarrassed 5 minutes from now. So why waste so much time & energy worried about it?