Georgiabelle thank you for the advice. Your last statement really hit home and I have to always remember that. As much as I stay busy with the little ones and plan activities, my mind gets lost in the madness that is happening around me. Just for the reason you state alone, that my kids are this age only once, I need to be in the moment more and enjoy life more. They matter too much for all of H's BS to take precedent. I have to genuinely live and enjoy life as if he's never coming back.
With each passing day I'm definitely "getting" that H really doesn't notice me or what I'm doing. Initially he did, but as the days and weeks go I see he's just going deeper into his crisis and into his tunnel where he no longer even has the capacity to notice. It's like there's already so much in his head there's no room for me. So to answer my own question, what I do (outside of going crazy and throwing him out) really won't make a difference. Thanks for putting it all in perspective!
Me: 35, H: 36, M: 6, S: 1, D: 3, BD: 4/21/14 H still living at home