nitabug, it's entirely understandable that your mind is spinning with the possible worst-case scenarios.
I was an active alcoholic for many years, and got myself into a pickle or two. Or three thousand.
I always got myself back out, sometimes the worse for wear. In all that time, I figured drinking is what I did and what everyone did. Little did I see at first that I drank a lot more than most people. I had to have serious issues before I was ready to quit. Several wrecked cars, scrapes with the law, medical emergencies, r e a l l y bad decisions while drinking that I won't even go into - but lots of consequences piled up in my twenties before I quit in my early thirties. So, about 17-18 years of bad choices and bad consequences. Who knows where on the line this guy is. It could go on for 20 more or 40 more years. You ready for that?
Sadly, many people do not make it out alive. It's often said in AA meetings that if an alcoholic continues to drink they have three places they'll end up: jail, institutions or six feet under. He may or may not ever seek recovery, and if he does it won't be because you made it happen. None of us have that kind of power over another.
I've known many who have died of this, whether it be from diseased body or accident or foul play - it's just a dangerous life for him, and for you. I'm sure he is making epically bad decisions all-around. Have you thought of who he may be sharing a bed with when he's blacked out drunk? I guarantee he #1. Won't remember and #2. Wouldn't confess to you.
You've stated your intentions with him. Now you have to let him make his own grown-ass man decisions.
In addition to, "Let go and let God," I would say, "Let go or be dragged."