Hi KM, you are the lucky one to realize a problem with alcohol at an early age. You say all your friends are heavy drinkers but not alcoholics. Chances are that some of them are, they just have not realized it yet. It took me until about age 35 to admit to myself I was a problem drinker....and took another 18 years after that to finally quit once and for all. I'm 53 now and 5 months without a drop.
Consider yourself blessed to realize at an early age and consider yourself more blessed if you give it up at an early age.
Good luck.........