Thanks so much everyone. I knew today would be a challenge for me, but I wasn't expecting this particular turn. It's awful because I was given this info in strict confidence and can't say a word to anyone, so I'm suffering with it alone. I'll have to face my friend as if nothing is wrong for the next couple of weeks and that is going to kill me.
My body is screaming at me to drink, but my mind knows it's not the answer. I'm still at work so still in the danger zone, but my plan is to get home, change clothes, and go for a walk or to the gym (hopefully without buying a bottle on the way home).