We are now in December, that time of year when audition anxiety can be at its height (particularly since so many Young Artist Programs have auditions during this time)
Whether you are main stage auditioning or doing Young Artist Auditions, it's important to remember that you are in a business where success percentages are not high - this being the case, you have to take a serious look at what constitutes success - this will help you get through it a lot better.
To use an analogy, in baseball, players get multi year contracts when they are successful getting base hits 3 out of every ten times at bat. If you think of an audition as an at bat, realize that in the opera/classical music business, "success" may be more accurately portrayed as 1 or 2 times out of ten.
If you allow yourself to look at it in this way, you will feel less angst over each and every audition - you'll be able to take a "big picture" approach.
In the long run, I believe this makes for better individual auditions, because the weight of expectation will not be squarely sitting on each one.