I am for sure not a vet, but I have a possible 180 idea for you. Next time H loses his keys, phone, etc. and all the chaos is ensuing maybe try ignoring him. (I don't mean rudely) but just remove yourself from the equation somehow, like when you see it coming, see if you can slip away until everyone calms down. Go take a bath, lie down, keep yourself busy with something else in another room. Whatever you have to do. Can you take said dog for a walk during said situation?
I read something a while back about a woman who was constantly running into conflicts with her husband over his lost keys and other items, so the next time he was walking around the house in a panic trying to find his keys, etc. she just ignored him and didn't intervene and it apparently worked in terms of reducing their conflict. Every situation is different though and you mentioned your H asks you where his phone and keys are.
Just wanted to chime in a quick thought. I understand about the resentfulness of the limbo. That's where I'm at. The marriage is over, but when I see H with his ring on and nothing's been filed yet, I think, is it really over? That's when I know I need to detach. But the limbo thing sux, I know.
Me: 38 H: 43 Kids: 2,4 T10 M6 BD: 1/14 11/14: H moves out