Hi cp85rn, reading your story and it sounds so familiar in so many ways. About telling his Dad? My guess is that he already knows or is at least suspicious. You said he's a sober alcoholic, so his antenna are probably already up when it comes to his son's drinking. I would most definately talk to him about it.
You don't mention that you've started a family yet and nobody can tell you what to do, but IMO be thankful you have no children in the situation. It will be just as much of a hell for them as it is...or will become, for you if you stay with him.
For myself, after living 20 years with an A who has gotten worse and worse over the years, if I knew then what I know (and live with) now, I would have never become apart of his whole mess. Those 3 C's are the bain of my existance and learning to accept them is one of the hardest things I will ever do but I'm working on it. Living like that is condemning yourself to a life of grief and frustration.