Chris, I can understand the real difficulty of being what is needed from you when you're utterly exhausted and feeling kind of lost. I've been there a few times, but without children, and I can imagine it is a million times harder when you know you're responsible for other little lives while still struggling through your own pain. Though I'm not 30 yet, I've experienced some pretty big and bad shocks, and I can relate to what you say about the feeling of withdrawal. When I have felt the way you describe (even to the rocking and staring, which I have also done), it tends to be because I am in a combination of depression and shock.
I wish I could say when it will get easier for you, to say that the pain will just evaporate. I can only say that for me, over time, the pain lessened, the shock lessened. I had to face, over and over, the things that caused this until it became real enough for me to process it. In time, I only faced days here and there, not too often, that I was exhausted by it all. All I could do was pray-- for strength, for peace, for making through another day.
Joy comes again... the sun always rises. It is just sometimes a long dark night before we see the dawn.
If you were here, I'd give you some dinner and a big hug (yep, despite having never met you!). But since you're not, I can only send virtual hugs your way and share a few tears with you.
Love and Peace,
Kim