Ugliness is Life's Daily B*tchslap. It's a serious problem for me, too, but most people trivialize it.
Otoh, I don't know what you look like, and it's possible that you have BDD (body dysmorphic disorder). If you think ugliness is the reason for your social anxiety, you might want to talk to a therapist about it if you haven't. BDD can seriously **** people over and is often comorbid with SAD, MDD, OCD, substance abuse and other issues.
For forty-seven years I've put up with it now. I must stop Christmas from coming ... but how?