I'm glad you posted this because it's currently the thing that's making me most mad. I feel so envious of those people who can just have a couple of drinks. Last night, I went out to dinner and I saw this glass of wine coming toward my table and I felt this huge sense of relief before I realized it wasn't for me. When the server sat it down at this other table, I just thought, "Wow. To have a glass of wine with dinner. A GLASS, ONE GLASS of wine."
I am in academia and my partner's in film and, in our social circle, no socializing is complete without booze. (I went to my sister's bridal shower last month in another town and was SHOCKED that there wasn't alcohol, though it was probably a good thing.) I, too, am trying to figure out what to do and say starting tomorrow night when the drinks come out. (I haven't socialized this whole week just to get a good start on sobriety.) I don't want to drink and I won't: I don't want to be sloppy drunk and there's no in between for me, I've tried. But, yes, I feel you on the mystification and envy at these people.
You and I both need to start collecting sober friends. I've realized I don't have a single friend, not one, that I don't get drunk with.
Anyway, hang in there! I know we both can keep plugging.