I'm sorry, LR, that its been such a tough year for you, esp wrt this relationship. It's hard to fathom that he wouldn't even notice a change for so long. It sounds like you were pretty successful at building a working routine for yourself and your family despite his absence, though it must have been exhausting.
Re "the hardest part is that I want to ask a million questions" - kind of a relief to read that, as I sit here with my own million questions, and try to rein them in.
In particular, I wonder whether he's having some difficulty that is larger than the situation at work. The Hawaii trip sounds weird. I don't get a good sense of whether at other times GG was happy with the state of his life, at least until he realized you'd pulled back.
Is it possible to ask questions that don't have an "answer that you want to hear", questions that are simply aimed at helping him to sort out his issues?
Re "he understands why it was over" - it's unclear to me whether either or both of you believes that the current shift is irrevocable. I hope he doesn't let a misperception stand in the way of his taking action, if there is a chance for you to reengage.
The current state does not sound stable. Although you have adapted to his non-participation in your life and are taking care of your own needs and interests, you sound far from a "new normal". I hope you can create one that is more satisfying than the current situation. And I hope that the fact that he has finally woken up a little bit can be the start of some positive change.