How you see yourself on the inside – your self-image – affects how you perform outside. Positive and productive inside equals positive and productive outside. If you see yourself as unpopular or insecure, your outside persona will reflect the same.
To overcome any negative self-image aspects, fill your mind with positive images of yourself performing at your very best, and hold them there. Then relax. When you have to perform later, your subconscious will remember!