A - Please, let's not get too dramatic lol. Of course you're not doomed. To a certain degree, you have become relatively insensitive to the workout situation, meaning that most times a regular training athlete doesn't get too nervous with butterflies before workouts. However, unless you're a vulcan, this is definitely not the case in the hours, and even days before a race.
When one is preparing oneself for an important performance - a moment of truth - it can often result in a myriad of physiological and psychological responses. One of the areas that is greatly affected is the gasto-intestinal tract since blood is dramatically shunted away to other parts of the body to prepare for the impending "battle"- so the GI tract's functioning is reduced which means that food and drink that has been eaten within a few hours of the event will not be digested as usual.
This is why it's important perhaps to enter more ("off Broadway") races, so as to experiment with, and to learn when, what and how much food and drink can be taken in. Such "dress rehearsals" also provide the opportunity to practise emotional control and to effectively reduce the stimulation level on the day of the big one.
May you get your butterflies in formation.