Let's say for a moment that he truly believes he can only get sober with your help and support. He's wrong. You can support him, perhaps in some ways help him. But the hard work of sobriety is on him.
What he is doing is setting himself for failure and continued drinking because you left. You didn't help.
This is more than manipulation. This is hitting you where is hurts because it is clear you really care for this guy. That is cruelty. That is alcoholic behaviour.
The only person you can fix is you. I wish you the best.