The social anxiety issue that u are experiencing has to do with your physical appearance, and obviously this social anxiety started with u since u were a kid, and as I read from your thread it got worst when u reached the secondary school phase, within u suffered from agoraphobia for the next 7 years,
And what made the situation worst with you is the comments! Repetitive comments from PPL in your environment! Family, friends...even from innocent kids! Kids they say the truth basing on their spontaneous background, they don't know that could hurt some body's feelings,
mentally u are already fragile and allergic and susceptible to the least spark when it has to do with telling u random words related to your physical aspect, then u found urself forced to endure living such embarrassing and better to say frustrating moments!
I bet you even didn't believe all people who told u you look beautiful in that dress! Or they liked your hair cut! Positive comments!
Have some questions to ask you,
Have u been avoiding mirrors?
Have u been excessively changing clothes? Makeup?
What parts in your face u consider ugly and have u thought about seeking aesthetical surgery? Or it is as u said you believe that your face don't go together with sunglasses or hats...?
When u were attending a social meeting have u ever thought about what the others may think of you? ( your face, your hair...)
Have u been spending lot of time comparing yourself with others, siblings, friends for example?