I was a functioning alcoholic for 15 years. Sometimes, those of us who come from alcoholic families have an amazing constitution for the stuff and can function long after most people - but make no mistake, you are still damaging yourself physically, mentally, emotionally, financially and affecting your loved ones.
I even had people close to me still thinking I didn't have a problem long after even I had realised I was in trouble. They said I was chatting to them fine and holding conversations perfectly in their eyes (only I knew the next morning I blacked-out about 2 or 3 hours of that evening!).
When I expressed my concern to my father and how I was getting crushing depressions the next day which I had never had before, he warned me that that was how my uncle's functioning alcoholism took a turn for the worse. He never overcame his problem, despite several rehabs, seizures, the whole nine yards. He was such a clever, kind, intelligent man, but this was his Achilles' heel.
People see alcoholics in the gutter and think it'll never happen to them. How do you think those poor souls started? No-one sets out to be an alcoholic, it's a continuum and sometimes you can be in quite deep before you realise where you are.
Like I said in a previous post, if there are underlying issues causing you to drink, these can be addressed. Please don't think you have to suffer stress without release - there are healthy stress-relieving techniques.
I am afraid this post may sound too preachy and was tempted to delete it, but I think I'll leave it to stand. I really do wish you the best, OP - you truly have done the right thing. 