Stress is a perfectly normal human reaction to what goes on at a FIRST event. And its not just the drive team, its the whole team
imagine being the team "Empress of Lodging and Nurishment" standing at the check-in desk at the Holiday Inn in Cleveland Ohio, with 50 team mates, mentors and parents standing behind you
and hearing "the computer shows you have 10 rooms booked in Cleveland New Mexico, not Cleveland Ohio:
The point is, it takes the whole team to get that robot on the playfield. Every year, the night before our 1st event we sat down and explained to the team that " if we win, we win as a team, and if we lose, we lose at as a team - but win or lose we are all going home on that bus saturday night, as a team"
if your design team did an outstanding job then the robot would practically drive itself. If the fabrication team did an outstanding job then you would have 4 weeks of driver practice before your event... You get the idea - no single person is responsible for the success, or the failures your team will have.
BTW, the result of stress that has no resolution = depression! you would not expect that, so make sure your team has plenty of time to blow off steam, exercise or goto the hotel pool, goto the team party and dance the night away - whatever it takes to resolve that 'flight or fight' instinct.