Thanks for all comments above.

I just googled "compassion fatigue," which I hadn't heard of before. Some of what I read reflected my own experience.

This is like over 3 years without a real break, except a few hours here and there. And lately he had two acute medical crises within a two month period. Worrisome things keep popping up, like in a game of whack-a-mole. Like last night he seemed to be having a TIA, as he was having trouble speaking. He took hold of my hand, like he was trying to convey with his hand what he couldn't say. By this morning, that was resolved. Then this evening he has had a disturbing cough with odd copious mucus production that he couldn't seem to clear, like he might have a mucus plug blocking part of his lung. It gets to where I don't even feel my own knowledge base is adequate to sufficiently assess what is going on. And we're both burned out on going in to the emergency room.

Tired now and going to bed.