my alcoholic husband has relapsed

My husband was so bad with his drinking that he caused liver damage. His sperm count was zero. He was sneaking it, hiding it everywhere, and constantly lying. I was tired of cleaning up after him and being berated, so I kicked him out. I told him I loved him unconditionally, but that doesn't mean I will watch him kill himself.
After that, he hit rock bottom, but he did go to rehab and get treatment. He looked better than ever before. He worked on himself and getting a job after treatment. I let him back in after many talks of being open and honest from this point. He came back home in September.
I have had gut feelings that he was drinking again because the way he was acting and talking after being back a few weeks. I caught him drinking numerous times since mid November. He will blow it off. He has started hiding it again and will not be honest with me. I found out that this has dated back further than that. Til at least mid October. 
I am heartbroken and disappointed. Not only in him, but myself. I wanted to have faith that we were strong enough together. But we aren't. The verbal comments he makes to me, breaks me down. Today I called a lawyer to figure out how to go about dissolving the marriage.
This time I feel more certain and calm in the decision. I know I have tried all I can, but I can't change him.
I am doing the right thing.