Unfortunately, standing by someone when they need help doesn't mean they will appreciate it. This is true in general, not just with alcoholics, of course. Best only to give of your compassion with no expectations.
I don't know if he was sober, but maybe he has gone back to drinking, maybe he has just wandered off to drink some more. He has never been the most reliable person, so that isn't a surprise really.
This is who he is, distance from him is perhaps a good idea for you. You don't need to let him hurt you anymore.