I am sorry your going through this, but he has to help himself first and want to quit. Getting smashed every single night is a serious problem. You have only been with him a few months? Is his drug counselling forced? My suggestion to you is think long and hard about if you really want this relationship if he is going to continue this type of behaviour, things usually get worse, your in the honeymoon phase now. Please take care of yourself ok.
He'll never be able to "cut back" on his drinking. It just doesn't work that way. Alcohol is a drug just like the others and is just as dangerous. I never liked alcohol. In fact, I've been drunk enough times to count on one hand. However, I plan to never drink again. Why? Because the brain has no way to differentiate between the chemicals that I use to alter my mood. You're discovering that addiction actually has very little to do with the substances we take. It's a mental disease that changes the very way we think. Changing from one drug to another is called cross-addiction, and is very common unfortunately. I'd suggest having a long talk with your boyfriends counselors and alert them to his cross addiction. Either he's not getting the correct information, they don't know what he's doing, or he's just ignoring their suggestions. NA meetings may be a good idea, too. NA makes a clear point that alcohol isn't thought of as a different substance, it's a drug just like all others.