Water - guess for once I have to disagree with Wiley (sorry darlin' )
I think you know your H is in a terrible depression and the attendant fog. I think you also know that your H is trying to reach out to you through that fog, and has been making steps forward ever since the D. Sure, he's still a mess, and you'd be totally justified if you wanted to move on without him, but since you still want to give him a chance, I think being MORE responsive to him when he reaches out (I would have hopped on that plane when he invited you!) is the way to go.
Sure, you want him to make plans more in advance with you but HE'S NOT CAPABLE at the moment.
And his earlier lashing out at you is just him projecting his own guilt and pain onto you.
I think it's okay to say "look, if you want to date me exclusively, then I would like X, Y, and Z - if you're not willing, then I may see other people at the same time."