Tell him straight! " I've fallen out of love with you, your drinking has become too much of a burden on me" If he tries to say something like: "I'll stop for you baby" Just say"I want you to stop for YOU and right now we are two different wave lengths ..I need to move forward with my life and you do too.. in the healthiest way possible ..I don't see this ending well for us if we continue on dating" I hope that helps?