Highly recommend practising some stoicism my good person.
You can control: 1. Your actions and reactions 2. Your desires 3. Your character 4. How you treat others
Everything else is outside your control and not worth worrying about.
Do you need to speak or perform? Is the audiences reaction to your performance within your control? No. Are the audiences opinion of you as a person within your control? No.
Is your anxiety within your control? Partially. Is preparing a good speech or performance within your control? Yes Is your character and how you present yourself within your control? Yes. Do you present well? Speak well? Are person of good character worth listening to? Do you treat others well and with respect?
Prepare and perform the best you can, be of good character and treat others well and anything outside of that is not in your control and not worth worry about.