[quote name='karmapolice']My friends 22 so I can get it everyday (and usually do). Bad habbit, but even so I shouldnt be able to drink as much as I can... It scares me... Im sure my liver will fail too early.[/QUOTE]
Thats what happens with alcoholics, their tolerance increases. If the liver gets heavily damaged though, as happens over years in many alcoholics (and the amount you indicate I think would put you in this group), tolerance plummets because the liver can't function properly. This means you'll have very high blood alcohol levels even though you haven't had much to drink.
I can't imagine a 17 year old downing 15-20, and it doesn't exactly seem odd for you.