As with any activity that requires you to perform in front of other people, GMing can be nerve-wracking. Some amount of nervousness is to be expected, but when your fears overwhelm you and you consider cancelling the session at the last minute, you can unwittingly put your entire campaign in jeopardy.
Many of us creative types know how anxiety and depression can interfere with the way we want to live our lives. If you haven’t already heard Wil Wheaton’s powerful talk on anxiety, depression, and recovery, you owe it to yourself to have a listen. Our inner demons are insidious, but you can empower yourself to mitigate their effects on your game.