As human beings, we often get so caught up in our daily lives and what's going on in the world around us that we forget that we are just that: human. Someone will always have something bigger and better, you'll probably dislike something about yourself or your life at some point, and people will continue to put images and ideas out there of how we're supposed to look, act, think, and feel. We get so caught up in these completely irrelevant things that we forget to feel good about who we are, what we have, and where we are in life.
The best thing you can do for yourself is to do what makes you happy. Choose the major you enjoy, not the one that will make you a lot of money. Eat the food you want to eat, whether it's greens or goodies. Wear what you want to wear since you're the one that has to be comfortable. And be with you want to be with, no matter what anybody else says or thinks. If all those things make you excited to get up in the morning, make you smile when you think about them—even when you're stressed—and you know will make you happy in the long run, then that's all that matters. There will be times that you go against everything people are telling you to do. But we are all only human, and we will make mistakes. No one will always agree or like what you like.
As Dr. Seuss once said, "Be who you are, and say what you feel because those who mind don't matter and those who matter don't mind."
So when something doesn't go the way you planned, or your parents disagree with one of your decisions, remember that it is your life, and you need to do what's going to make you happy. And in doing so, you may make some mistakes, but again we are all only human.