Congratulations Punchy Astronaut!

"WE'RE GONNA FUCKIN' DIE IN THIS THING, MAN!"

Your fellow astronauts will be so used to this sort of behavior by now that they won't even turn to look at you.  They'll just roll their eyes at one another.

It all started back during Introduction to Being in Space and Stuff, the first class any aspiring astronaut has to take.  You spent about twenty minutes in a chamber designed to assess your ability to manage under claustrophobic conditions and had a psychotic break that set the tone for the entirety of your astronaut training.  If you were any less exceptional a candidate, with first rate scores in maths, sciencing, and fixing things, you would've been washed right then and there, but thanks to your remarkable qualifications you're on a rocket into space quite literally, at this moment, and you are losing your shit.

"LET ME OUT!" you'll scream at your cohorts.  "UNSTRAP MY SHIT BROS!"

They'll ignore you.  They know better.  Ever since you snapped during training and started beating the shit out of anyone you could get your hands on, they knew you couldn't be trusted.  They also know that you won't calm down until you've been in zero gravity for at least a day, at which point you'll begin to laugh like a child.  Once you're in that state of wonderment, you'll be able to perform necessary tasks with total reliability and acuity, but the interim period, this interim period, will be a living hell for your co-workers and a furtive nightmare sparking at the edges of your consciousness for you.

We recommend imagining that you're in some sort of deep-sea diving suit to try and ease the tension.  Once you're actually in space, you'll be fine - you won't murder the entire space station, the way some of the brass down at Space Command thought you might.  You won't invent crew members and become emotionally invested in them and then lose your shit when you realize they're not real, the way the psychologist who examined you before you began training thought you might.  You'll perform as an exemplary astronaut, once you're in orbit, though your condition will render you absolutely incapable of independent thought, little more than a child really.

This is for the best, however.  Left to your own devices, your spiraling intellect would begin to twist reality and turn your easy space voyage into a mental prison from which you long to escape, and you'd end up doing both those things we just mentioned, which would really put a damper on all the space-fun your crew mates are planning on having once they arrive at the international space station.

Congratulations Punchy Astronaut!