I think it's good to recognise that you possibly have a problem at your age; you're obviously a bright bloke.
At your age I drank till I was oblivious at every given opportunity and didn't realise that this wasn't normal behavior. I obviously wasn't a bright bloke.
But don't think that because you're only 20 you can't be an alcoholic; we've got quite a few young people in my homegroup AA and I remember thinking, 'No way, you're far to young to be an alcoholic', but when I heard some of their shares; they wouldn't have made it to my age the way they were drinking; I mean one of them used to take drugs so he could force more alcohol down his kneck. I just used to pass out at some point; the lightweight I am!
Good luck, and at least consider the 30 day thing; you've nothing to lose?