How do I get my parents to back off?

I am a 17 year old girl, I turn 18 in 1 month. My parents signed an early graduation paper saying that I may graduate early in March of 2013. Everything was signed I was good to go, I turned the papers into the office, figured out my schedule. Everything Perfect. I’m taking Human Anatomy and Advanced Mathematics at the high school and taking two college classes at the college in my town.

HOWEVER today I explained to my mom that I am only taking two college classes. She flipped buckets. She freaked out exclaiming that I told her that I was taking three. I said I was going to take three but my counselor advised not to because of the classes I am taking. She said "THAT’S IT, YOU’RE NOT GRADUATING EARLY" I was like WTF mom? You’re getting mad because I’m not taking 3 college classes? and arent going to let me graduate? how Is ONE college class, Just ONE going to help me in the long run?

I NEED to get out of this house, it is a complete h*ll hole in the first place. The sooner I get out the better. My mom explained to me later when she was crying that she didn’t want me to make the same mistakes she did and I was like oh, what were those? She said she had s*x before she was married and didnt want that to happen to me. I was like there Is NOOOO way I am going to be like you, you don’t have to worry. When she was 13, she smoked, when she was in her teens she did Marijana. I plug my nose when I smell smoke, and im too much of a wuss to do drugs.

Just give me advice, please please..