I can feel the pain and confusion in your post.
I don't mean to sound harsh but when I read your post it seems to me like, in this case, his words and actions are kind of matching up. He is not going to move further with this relationship. I'm sorry that hurts and is in contrast to how he started the relationship but chasing him down is going to add to your pain. He is in no way fit for a relationship right now and even he sees it. He is an alcoholic. He is already committed - to alcohol.
He is saying "I love you." to make himself feel better. He doesn't have to own up to anything. Does this look or feel like love though? It doesn't to me. You deserve the real thing, from a man that is not a basket full of dysfunction and confusion.
What if you took all this energy and, instead of going round and round over what he is thinking, focus on you. Your wonderful self and how
you can love and cherish
yourself. It will be worth it.