When we are anxious our stress hormone cortisol rises. The heart pumps faster, we feel hot, and we sweat.
The thing is, this very same body mechanism also happens when we are excited.
So instead of telling ourselves that we are anxious, repeat in your mind "I'm excited, I'm excited, I'm excited." This is called the anxiety reappraisal. Research showed that people who were made to do this during nerve wracking situations performed well and better than the others.
This is the power of our mind. We are in power of what to label what we are feeling.