Can you tell me how to overcome performance anxiety and public speaking anxiety?

There are a few : Techniques that can work fairly quickly. Cognitive behavioral therapy using progressive desensitization (learning to relax ; then imagining the phobic event (public speaking) from least to most anxiety provoking image while relaxed. I usually do this using hypnosis as a relaxation technique, but you can use other relaxation methods. Find a therapist ; you will be able to get relief fairly quickly.

VRT for Phobias: Phobias and anxieties respond well to Virtual Reality Therapy(VRT). VRT is exposure therapy in a safe environment. The research suggests VRT is 90% effective. Seek out a therapist who uses VRT in your area. You can find providers through www.psious.com, www.limbix.com, or www.virtuallybetter.com.