While I can't say anything about your specific situation, I will say this: I started drinking during my freshman year in college (I'm also a girl), and within two years was a rock-bottom alcoholic. We do tend to progress faster than the men, on average. My major worry, with myself as well as you, is that the young brain is very plastic -- it doesn't stop developing until our early to mid-twenties. Even if you're not an addict, my concern would be how you're affecting your neurological development.
Also drawing on my own experience (and I truly don't mean this to be a scare tactic)... When I was drinking heavily, I fell into a relationship with a guy who, in retrospect, was coercing me into sex that I didn't want (read: raping me) on a regular basis. As young women, we are more vulnerable to predators when we're under the influence than a lot of other people.
My advice would be to talk to a school counselor or some equivalent, if you truly don't feel you can talk to your parents about this. You are certainly not the only one in your age group going through this sort of thing.
Even if I am able to resist for 6 months or something, I can't forever, eventually I am going to do it again, and once I get a taste of the feeling again I'm not gonna want to stop.
Boy, that does sound familiar.
