Thank you all for your thoughtful, and painful, responses. I am deeply afraid that you are right, so I'm probably looking for evidence that it doesn't "have to" be that way. At least I can see the breakdown in my logic, even if I can't get by it yet.
CarryOn, we are in very similar situations. I didn't understand it at the time but I lived with a dry drunk for five or six years before relapsed. It began with, "we're on vacation and I think I can handle a drink," and went to *secret* drinking evry day very quickly, within months. About a year ago he stopped pretending he wasn't. Drinks til bedtime most nights, with a real bender thrown in every few weeks, generally if hes upset about something. After one of those, we might get a day without drinking, but im usually too shell shocked to enjoy it. He's a good person and that good person is still in there, but he sure hides it well sometimes.
It's probably pretty telling that I don't go to Alanon mtgs because I don't want to deal with listening to his reaction. I do go to therapy and read a lot about this stuff though. I'm learning and putting the knowledge in action when I can.