MI, I think the tiredness has the most to do with it. It drags you down into a rut where you can't see the wood for the trees. Once you can get a few good nights under your belt, it's easier to tackle the rest.
I only help when asked, so actually end up doing more with the 16 yo than the 8 yo, just because that's what's needed. So don't beat yourself up for not going through homework; imo, you're not supposed to go through homework, unless they need you to.
Dog update: he has a huge left side to his heart, with a non-functioning valve, so lots of liquid sloshing through and back, which has made it expand. He also has pneumonia, which is being treated. So he might just have to be a more sedate dog on medication, or he might keel over. Not sure at the moment so it's wait and see. I suspect if we make it through the next month or so, we might be OK till the next infection. Still, he's very happy, no pain and chilling on the sofa.
Oh and we've inherited a piano.......
. Not sure of the timing of poorly heart attack dog and noisy piano, but hey ho.