When you’re doing vocal production for a project it’s easy to feel pressure.
But the performers are under pressure too, and understanding that (and the position you’re in respective to them) is why it’s so important to be kind and not present any of the internal stress you’re dealing with. Showing performers you’re stressed serves no purpose; it will make them stressed, and being in front of a microphone with someone dissecting every take you do is already a stressful position to be in.
Even if you’re in a situation where you’re frustrated about something, does voicing that frustration help maintain or increase the quality of work that is being done? If the answer is no, keep your mouth shut, act like your inner world isn’t imploding, and solve the problem. Are you going to let your emotions degrade the quality of the final product?
Attitude is a skill. Take a deep breath and then get on with it.