I'm a social anxiety sufferer. Similar to you, I'm sure mine dates back to when I was ridiculed back when I moved to my town for just about everything (namely nerdiness, shyness, fashion sense, etc.) I also have severe lung problems that would result in coughing excessively - people made fun of me for that, too.
Unfortunately, my social anxiety almost controls my life now. My advice would be to seek help for it in case things end up getting worse, ya' know? I didn't use to be so bad years ago, but now I wish I could start seeing my psychologist again.