Hi Sally,
I would say he definitely has alcohol issues. You only see what he allows you to see, he may be drinking every day, just not to the point of obliteration. It sounds as though you made up your mind by obtaining the legal separation. He will not change until HE decides to, IF he decides to. You already have 1 foot out the door and no children. Why stay? It will continue to get worse, as alcoholism is a progressive disease, unless he is willing to make concessions with his alcohol intake.
I wish you strength with this difficult decision.