Current situation is not working for either of you. This is not a man in crisis but he is stuck. As long as OP keeps doing it all, he will keep dy nothing. The fear is that he will spiral more, if do then maybe she can get him serious help. But my bet is that he dies just fine without the marriage supporting him. It's worth the risk either way since oP cannot /is not helping now but is herself at risk.
And the cancer posts are a terrible comparison. Only if the person refused treatment but then expected beveryone to drop everything because they were I'll is it similar.