Is this a sign that I'm becoming an alcoholic?

Well im 17 years old and I don't drink on a regular basis (only because I don't have access to alcohol and most of my friends don't drink). But when I do get the chance I do drink to get drunk. Anyway well I had slept over my friend's house and it was early in the morning and her parents were gone. My friend was in the bathroom and I said I was going downstairs to get some breakfast. Well I noticed her parents had some boxed wine so I grabbed a gl and chugged two cups of it as fast as I could. I know that is sickening but I wanted somethink to take the edge off because I've been stressed. Now I feel bad for what I did and I'm worried I might become an alcoholic? What do you guys thin?