It could be
That you’ve didn’t practice enough
That you didn’t have a standing ovation
That your expectations are unrealistically high
That you didn’t meet someone’s expectation
That the expectations were unclear
That you’re trying to be everything to everyone
Consider the oldest and most successful book. Even the bible has one star reviews, who do you think you are?
Chances are, you can’t achieve every expectation of you. It’s a trap to try and win that game. So it comes down to your inner expectation of yourself, then aligning it with the other. Accepting the ones you can achieve.
It is first to look within and figure out those expectations, to see if they are realistic and if it is what you wanted in the first place. Solidify your own standard, the courage will come.
Sometimes, the most important job is an inside job.