Social anxiety disorder is an illusion that only you can see. It's your perception of how the world sees you, your interpretation of the future, your thoughts floating around in people's heads. The illusion that everyone's eyes and attention are on you at all times, however this couldn't be further from the truth. In reality, in the eyes of everyone you're just another person in the crowd of people. Everyone has their own thoughts and their own concerns going on in their heads, the illusion is you believing they're about you. Sure, maybe someone sees you and forms a quick opinion or thought like "I feel like I've seen that person before" or "I like that shirt he's wearing", but almost immediately after they go back to what they were thinking or start a new train of thoughts unrelated to you.
Don't believe me? Think about how you see and judge random people you see. Think about how you see and judge people you know. While a person with SA is more likely to think about people longer, ultimately you stop thinking and judging them and move on with your life. If you're worried about random people you don't know judging you, you really have nothing to worry about. Even if they are thinking about you, they don't know you and thus can't pass accurate judgement. It's usually just a quick thought that leads to another, afterwords you are no longer in the person's thoughts and probably never will be again. You are the only person thinking about that embarrassing thing you did that you think everyone is judging you about, you are the only one still thinking about it. Haven't you seen someone mess up before? Notice how you forgot up until I had you remember? It's the same with other people, you're not as special as you think, you are not the center of the universe.
Another illusion is that you are living in a different time compared to everyone else. People with anxiety are always living in the future, worrying about things that haven't happened or probably won't even happen. It is pointless to worry about something that isn't currently happening, especially if you aren't even sure it is like someone thinking about something stupid you did. You're the only one who thinks that or will think of that unless it is brought to people's attention. Stop assuming you know what everyone is thinking, we each have our own thoughts and concerns that primarily affect us. I'm not thinking about the way my neighbor is dressed today, the little slip up a random person made while walking the other day, or judging a person walking down the street I don't know. Wake up from this world you live in that nobody else can see and come to the real world where people are actually nicer and couldn't really care less about how you look or do things like how you don't do the same to others.
This last piece of advice needs to be read with an open mind. If at any point when reading this paragraph your attitude completely changes to negative, notice it and try to think about why it happened. I cured my anxiety without the help of therapy or medication, what worked for me might not work for others. If therapy and meds aren't doing it for you or you don't want to take that route, there is still someone who can help you. Someone who knows you better than you know yourself, someone who loves you no matter what, even if at the moment you don't feel the same. Someone who knows the exact problem you are having and why you are having it, someone who knows your strengths and weaknesses who will use them to your advantage to help you. I'm of course talking about God. I was agnostic for 23 years of my life but that changed when I met God. He helped me cure my depression after my SA and so much more even after that. He is real and if you are thinking "Why has He allowed me to suffer if He loves me?" it's because of actions you yourself are currently taking. It wouldn't really be free will if God controlled all your life choices so they don't end up being bad. You have free will, God will show you the problems in your life by bringing them to your attention and guides you along the path to solving those problems. Ask Him for help but don't bargain or test God, don't say something like "I'll believe in you if you can cure my SA" or "If you are real, do this so I can be sure". If you want to meet God, you must be willing and open to the idea of Him existing. Your grudge with Him assuming you have one because of how your life currently is, is misdirected. For the sake of not making this thread any longer, if you have any questions on this feel free to let me know here on via PM.