How can I keep my mind at ease about my future?

I am a senior in high school, and college is just a few months away! At this point in time, I should be living it up, but I am not. I am worried, constantly worrying. I'm going to a second choice college, my first choice is out of state and no way can I afford it, and my parents want me to study medicine. My parents were immigrants, and I'm the first Vietnamese American to go to college. It's such a huge deal. I want to make them proud and I tried to force myself that being a doctor is my calling--it's not. I love them and they worked so hard, but I just don't want to live my life for them. My dream is to be a graphic novelist and/or voice actress, to travel the world, and live peacefully in Japan somewhere someday. But that's just it. It's just a dream. I've also been obsessing over my choice to be child free and already my mom is against the idea, saying I'll change my mind. She knows I am nervous with children. I'm not stupid enough to say that I will never, or absolutely. But the thing I would hate most is to give in to society pressure to have kids at a time when I don't want any and deeply regret it afterward. It makes me so depressed. I know I can and should live my own life, but I just can't bear the disappointment and criticism I will get for the way I want to live.