This makes, some sense. I am sorry, it's hard, sounds hard. I'd probably have a hard time, with it, too. Is there, something, about this time of the year, that he needs to resolve, within himself? Some people's depressions and addictions, et al, have some type of starting point. And, maybe, the holiday season, is it, for him? Christmas, was the first time, I ever actually drank, for the sake of drinking/to feel drunk. Never had a dx of alcoholism, but certainly, I can remember, vividly, what, why, when. It was a point of hopelessness.

I can, appreciate, how, he was to resolve what it means to him, to be dependent on another. Goal, of relationships, is a sense of interdependency.

If, you two, weren't on a rocky path, when he decided this, sounds like some type of either spiritual journey, healing journey, whatever you want to label it.

Will, he at least, stay in some type of contact with you? Albeit, minimal contact, like one might, while taking a business trip, or visiting family far away?