I'm dealing with this myself. I'm taking some risks, trying new things, some of it public, especially with my writing.
Practice helps, doing it helps, getting experience at being human out there in public, making mistakes even sometimes, and finding out that it really doesn't kill us. Even though it may feel that way.
I've learned to pay attention to how I talk to myself. For instance, currently criticism or acknowledgement can come in my email. I noticed that as I waited for email to open, I was steeling myself for the worst. And barely breathing.
So writing down my thoughts and coming up with alternatives is helping.
I am human, I have a right to be here, I do try my best, and it is okay if I make mistakes. I can notice my successes too.
Sometimes it helps if I think of myself as a scientist, a "mistake" is simply more information.
-I- am not a bad stupid person if I make a mistake. Neither are you.