I think you’ve done amazingly and been extremely supportive.
Sounds like the hospital may have given him a partial detox. You could request a discharge summary from the hospital and Chase up with GP for more guidance.
Usually with withdrawals it’s about drinking to what the body requires – so he’d need to learn to understand physical withdrawal and not psychological. In other words drink what you need and not what you want.
He should be grateful towards you as you sound really caring and supportive. It’s just sad you’re having to go through this. It’s awful I know. Devastating.
Don’t forget to take care of yourself and remember ultimately it’s his responsibility. Pleased he is going to AA zoom meetings, he could go to them all day if he wanted to keep his motivation going.