Thank you!
It was a very long process. I was in intensive talk therapy for years (not specifically anxiety-related but to work through the trauma)
At the beginning, propranolol was a lifesaver, because my biggest negative thought cycle was that people would see that I was anxious, and that would make me even more anxious, and I could push myself into a panic attack that way. With the propranolol I was confident that, even if I was nervous, I wouldn't physically show it, so it helped break that cycle.
I really leaned on relationships in which I already felt comfortable, to keep things in perspective and stop ruminating - because everyone has awkward moments and does stupid things. It helped me retell embarrassing moments in a funny way, and learn to laugh at myself rather than ruminate.
I tried to do as much as I was reasonably comfortable with - because the anxiety shrinks or expands to fit your comfort zone, so if you stop doing one thing, you become anxious about a smaller thing.
And finally, as I mentioned above, radical acceptance. This took a long time because with social anxiety it doesn't matter if other people say it isn't a big deal - it IS a big deal when you're going through it. I learned to accept that I had social anxiety and that was ok. (Before my trauma I never had anxiety and was a total attention-seeker, loved being on stage and meeting new people, etc, so I really judged myself and got angry at myself and felt like my life was ruined.)
You can also try anxiety meds - these never worked for me but they do for some people.
I only recently, finally got myself out of the rut of social anxiety and it's so freeing. If you keep working at it you can definitely crack it. Good luck x