Welcome sjnorth!
Just for comparison' sake
I started binge drinking in college, some 25 years ago. I was highly successful academically. I kept on drinking and telling myself it was perfectly normal. It slowed down in grad school at first, and I thought little of it, dealing with fuzzy mornings and headaches. I was highly "functional" achieving several degrees. Something happened in the past ten years, however, that I can only explain as evidence of the progressive nature of alcoholism. My tolerance became herculean; I almost prided myself on it. Then I started staying awake long after my wife went to bed, polishing off more wine in front of the tv, or pretending to have brilliant ideas in my study. Some nights I pulled all-nighters and faced the day still drunk. I was told to reel it in by wife and family. So I somewhat did, but I craved. In the last several years the power of control that I thought I had vanished completely. "Sure let's go have a few drinks"--these settings began turning into 5, 7, 10 day benders. Steady drip. Chugging down beers in the morning from the basement fridge while the family ate pancake breakfasts upstairs. Holding back the gag reflex to keep it down (and sometimes failing). No control whatsoever. All of these episodes followed by increasingly bad withdrawals, with me pacing the house or the walking the neighborhood in despair for hours on end. 2 ER visits for detox in the past two year and a half, the last of which shuttered the idea forever in my heart that I was "normal" or "functional." I know I am an alcoholic.
So I don't know about "functional." Most people who are healthy drinkers don't even need that qualifier I guess.
Apologies for the lengthy reply, but your post got me thinking about my own attempts to come to grips with my alcoholism.
Hope you don't mind the share. Best wishes