Very wise thread title. Never forget it, and never stop growing and becoming a better person.
Michele wrote about having sex with our spouse during this time. Maybe someone can post it (or a link to it) here for us.
Basically, she said if it would make you feel used, or otherwise bad, then you don't want to do it.
But, if you feel it could be a way for you both to connect in a loving way, then you may want to be open to the possibility, even if it's only occasionally... especially since you mentioned SSM being a past issue requiring your attention.
Plus, if I read you correctly, you're fairly certain H's not cake eating.
If all this is the case, I'd say rewarding positive behavior could go a long way to helping rebuild your marriage.
As always, monitor results.
"Really wish I could just hold him and tell him he can get through all this."
Why can't you? He's already holding you. Telling him you know he can get through this is not you trying to fix him... it's you showing you support and believe in him, and then leave him to it. This is what he needs from you now!
"Funny how my strength is coming back."
You should feel strong. Marriages that have made it past the 20 year mark have already weathered through most of the typical issues that end most marriages at the 7-8 year mark. You and your H learned how to resolve these marriage ending conflicts a long time ago. You have something worth saving! Even in his crisis, your H seems to be able to see this too.
And now you are both learning some new things. And once you get through the crisis your M will be even stronger than it ever was before.
Remember: The more steady, confident, and independent you are, the more H will be drawn to you. The more meaning and purpose you create in your life, the more attractive you will be. Keep On Bustin'.
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