Hey Natalie,
I first started going to AA when I was 18, and have been an active alcoholic/addict since I was about 16. So to answer your question, no you're not too young to be an alcoholic. Although my substance abuse didn't start until I was 15 or 16, I believe I had the disease much earlier. I felt different to others, like something wasn't quite right. And I suffered from anxiety and still have to work hard to keep it under control. Going to AA has literally saved my life. It's really an awesome place. But it's a day at a time. As it's been suggested, I think if you have thoughts about whether you might be an alcoholic, attend a few meetings and LISTEN CAREFULLY, and then make a decision to stick with them or go on your own. It can't hurt. At the end of the day honesty is the key.
Hope things go well with you,
Jeremy