What to do about my mom?

My mom is a control freak. I want to be a vegetarian or just try it for a month but she won't let me and I can't drive yet so I'm stuck eating whatever is in the house. I would really like to look into a Psychology program at a specialty school nearby but sh doesn't want me to be a psychologist so she wont let me. I'm trying not to sound bratty but I do want some control over my own life. She won't be there my whole life to make decisions for me and I need to learn how. Help?