No one can say if your H will make it though his crises or not. But I think we all agree that you ARE NOT a fool to be standing for your M! I can hardly think of a more noble thing to do: Stand by the one we love when they are in a major life crises.
My little bit of advice: Truth Darts. Start dropping little hints that you don't intend to live in this present limbo forever. Not because doing this will make H do a turnaround, (it won't, but that's ok for now) but because it will help you stand. It'll help you feel like you're "doing something" and having a say in where things are going... instead of feeling like a silent victim being taken for a ride.
I don't believe we have to STFU forever, especially when we are nearing the end of our rope, which it sounds to me like you are.
If you continue to stuff your true feelings around H you will end up giving up on the M before he comes around, or blowing up on him, which will likely send him further back into the tunnel.
Worst of all, after a long enough time of stuffing your feelings you will lose yourself.
There was a time when I felt like I was close to really letting loose on my W, and telling her what time it was. My DB coach advised that I say something rational and well thought out, at the right time, before I got to the point where I'd likely blow up and sabotage all my DB efforts.
Timing is EVERYTHING with truth darts. Move ahead slowly, but do move.
M: A really long time. Crisis: 5 years. She's still worth it.
Life is never made unbearable by circumstances, but only by lack of meaning and purpose. -Viktor Frankl
