There is a natural desire to have appreciation from the public for your performance. You are basically not afraid of the public rejecting you but you are afraid of you rejecting your own self. Love yourself for who you are. Give your best with love and faith. Do not worry about their reaction. What is important is the satisfaction that you did your best. There is a possibility of a past traumatic experience and you are scared of a repetition of the same. Heal it with Past life therapy and inner child therapy. I perform to please myself. Others appreciation is simply a bonus.