You're not hurting him, he's hurting you. How did that get twisted about in his mind? And when did he appoint you as controller of his life?
You've stated your boundaries so that discussion's been and done, and no need to repeat yourself. Now really think about this; is leaving the only option if he does start drinking again? Or now that he's self-medicating in other ways?
If you can't contemplate life with him drinking again, and it sounds like you won't go there, then you know where you stand, and so does he. But you seem to think you standing firm will stop him drinking, rather than it being for yourself and your own welfare.
From what you say, he may have already made up his mind, and is now bargaining about whether you stick around. Guilting you and wearing you down.