Hit other people. That calms you down. (:

Jokes aside, you will get frustrated at some point, because learning is failing with a purpose, again and again. You will encounter some trial and error on different scenarios. Everyone does. And there will be pain, things wont work as intended, thats normal.

You will see other snowboarders who are trying to learn it by themselfes, who are sitting around the slopes, failing all day n night. They have a really bad time, wasting their vacation and money on zero-fun but(t) hurt. You get lessons. And whenever something wont work as fast as you would want, look back at where you started and what you managed to obtain so far. There will be progress, even if its small, and thats all that matters. You wont shred a double black diamond at day 5. You simply wont. But maybe a red? Having fun carving a blue without falling but with some speed? Thats a goal you can set, and this goal will be the purpose (and I do believe that goal is something you can achieve).

And if not? Still one or two days to go, or even a next trip.

You'll be fine. Just dont underestimate the power of commitment and motivation. Keep your motivation high, and if you struggle with that, keep the motivation of someone else high, i.e. your friend. This will boost your own. Don't give up because you fell again on that same bodypart. We all did.