ah Highfunction...I knew you were a smart cookie when I read your first post. I'm glad to see you're still here, thinking, learning, debating and questioning. I'm also relieved to hear your GP didn't sugar coat things for you. Your ABF is suffering from a progressive disease, and unless he decides on his own to find recovery, supported by a recovery program, I seriously doubt he'll "get better".
I'm so sorry this is what you're facing.
Please try to remember, as you talk to him about his drinking that
You didn't cause the drinking
You can't cure the drinking
and you CAN'T CONTROL the drinking.
This is where detaching from the outcome of things comes in real handy. I know your future hangs on this man and his addiction, so it's very difficult to detach, but it is possible. It'll just take some time and practice to turn the focus away from him and on yourself.
I sincerely hope that your ABF finds his all important bottom one day and decides he's had it with drinking. Until then, keep coming back here, grab a copy of "Codependent No More" and perhaps find an Al-Anon meeting to attend.