Basically, go ahead and let yourself get anxious/excited. It’s OK! You might even enjoy yourself, in a way. They say “…getting excited helps with performance anxiety.”
"Although counter-intuitive [contrary to societal training, not counter-intuitive, if you ask me], getting excited helps with performance anxiety more than trying to calm down, and using certain statements can manufacture the remedy, creating major biochemical changes. There is a reason why not forcing oneself to calm down might work to improve our outlook."