Good luck fen.... I agree with ttpb that the fear is always worse than the reality, so go for it and be proud that you're doing the right thing.
It's tempting to want to put it in "nice" terms, but I don't think that would be wise in this case. So, don't downplay it. Just tell the whole truth- that's the only way your doctor can know how serious this is for you. And remember that doctor's see alcoholism every day, mostly in the form of denial - they probably love it when someone comes in and truly wants help.
We're behind you!