Everybody grows up with a fear of rejection which has something to do with being incorrect, inappropriate, etc. sometimes. Some people are damaged by fear/rejection and some people use it to build their confidence and people skills. Your early environment has a lot to do with how you perceive and manage fear and rejection. I watch analysts and guests on the news every night and wonder how they got to the point where they can appear so confident and relaxed (at whatever age they are at). I've performed below satisfactory on several professional jobs and always had fear of something inside or outside of me. Failure is a great motivator and tool to build on. Focus on proving people wrong and it will improve your self-worth and confidence.