I think you can train yourself to block out some of that pressure and replace it with confidence. It's about preparation, and the more prepared I am, the less pressure I feel and the more confident I am. As your confidence grows, it's only natural that the pressure you feel diminishes.
By a peculiar prerogative, not only each individual is making daily advances in the sciences, and may make advances in morality (which is the science, by way of eminence, of living well and being happy), but all mankind together is making a continual progress in proportion as the universe grows older. So that the whole human race, during the course of so many ages, may be considered as one man who never ceases to live and learn.