Jimmy Piersall was bipolar, which is/was even more debilitating.
Social Anxiety Disorder is very bad for an athlete or entertainer. When he quit taking Valium all the time, Andy Partridge of XTC discovered couldn't perform live because of severe anxiety. Most people get stage fright or are uncomfortable with public speaking with their initial efforts at it. Over time, with practice and repetition, a person will become more comfortable performing in public, some will learn embrace the rush of butterflies in the belly. Someone with SAD might never get comfortable their performance being watched/judged, or toggle back and forth between comfort and anxiety.