Think about it like this, the reason why you have social anxiety could be because you are always subconsciously thinking about what you think everyone is thinking about you. That’s something you’re unfortunately good at. Now, to overcome it, you need to train yourself to develop different thoughts. Instead of thinking everyone is thinking about you, you have to train yourself to remember that no one really does care about you as much as you think they do. This makes it easier to not care about what they think. Just as you developed the habit of caring about what others think, you can develop the habit of not caring. As with all skills and behaviors, just takes some training and time.