Hey, LWB -- First time here in a couple of weeks. I'm so sorry about your emotional roller coaster. I sure don't have as many wise words as other DBers do, some people here are truly amazing, but the one thing that came to my mind is cheeseless tunnels. You've been at this so long, perhaps requesting a separation is what is needed. I know it will make it easier for you. But your H has seen you floating on an even keel for a long time. This is really going to rock the boat. Perhaps it's what he really wants. But if he's not sure, this will definitely get the rocks in his head to tumble tumbling a lot faster.
I hope he 'hears' you when you tell him why you want to separate.