Hugs to you! I totally understand. I, too, noticed a pattern of when we'd be having issues or when he'd shut down in a depressive state. It was always tied to something at work: end of fiscal year, regional meetings, his boss flying in and driving with him, etc. And, Suki said it well, the "he's sick" stuff only goes so far if they aren't working a program or active in recovery. My AH is not doing anything to get himself better so it's quite frustrating to sit on the sidelines and watch the drama unfold knowing there's really nothing you can do about it.
Are you attending Al Anon? I find that meetings really help me feel positive and I gain insight there that helps me get through another day. So sorry you are struggling today!