Honestly, I think the term functioning alcoholic is a complete oxymoron. Yeah by all appearances I kept a great job, home, marriage, no duis.. many years ago I actually would mix vodka in my beer to make it 'stronger', from a hidden vodka bottle. I stopped that once hubby found the bottles. Fast forward a few years, add availability of hard liquor at a grocery store (its otherwise illegal), and I was hiding vodka again, but chugging it straight and chasing it with juice.
Then one weekend I got economical and bought a gallon huge bottle.. and drank on a @unday morning to chase the shakes. I woke up in the ER with my husband and parents crying at my bed. My bac was .568, and I should have been dead. This stuff is horrible, and progressive.
I started drinking again 3 weeks laster, deluding myself and huby that id never 'get like that again'. 2 months later I was driven home from work at 9am for being drunk at work. I don't even remember it. I haven't drank since.