Help me solve some mom troubles?

I love my mom. A lot. But there is an issue. My mom is a micromanager who tends to get very upset when people don't follow her directions. This was okay while I was a kid, thing is, I'm now 19. It's frustrating being told I have to follow her dress code (skirts meet the knee, shorts are fingertip length, no spaghetti straps, etc etc) when I work hard to keep a nice figure. It's frustrating not being allowed to listen to almost any music except clical or hymns. It's frustrating going into my room to find my personal notes, receipts, and items have been looked through and rearranged. She does a lot for me and I am extreemly grateful for the fact that I'm allowed to live in the house and my parents are putting me through college, but these things are always held over my head and used as an excuse for my lack of freedom. For example: I know you're buying your own clothing now but you can't buy things that I don't approve, even if you wear them when I'm not around because we're paying for college. I want to improve my situation in the most adult-like mature way possible but talking has never worked because she stops listening. Help. Thanks.