Be the best at what you do
Self confidence is a major lacking point in people with social anxiety. What I have found that has helped me is to be the best at whatever I do. Wake up in the morning and look forward to going to work. Lets say you work as a business consultant. Make goals for yourself, evaluate your surroundings, take note of your coworkers. Say to yourself "I want to sign deals with 50 clients this month and no one will *****ing stop me". By setting big goals you will never sell yourself short. And once you reach your goals you will have a feeling of accomplishment that no one can take from you. I personally have fitness, financial, and social goals for myself. I think its the best way to achieve them since you can visually see them every day. Write it in your notes on your phone, write it on your white board in your room, write it on the *****ing PB&J you make every morning. Just make sure you get it done. I recently achieved my $5000 mark goal from investments i made in cryptocurrencys and I'm going for $10,000 now. Goals like these distract you from the depressing thoughts of social anxiety, since your mind is constantly on improving whatever you enjoy.