Dagger, I can relate to "faking it" - I'm a substitute teacher, so I have a good excuse for not always knowing what's going on
but a lot of the time it really is the fog. One day I gave the kids (elementary) a list of spelling words, which then turned out to be the wrong list, so I had to do it over. Then when I actually needed that first list, it was nowhere to be found. And I'm ALWAYS misplacing my sub instructions. Getting the kids to explain math problems that elude me is a good trick.
I'm so sorry that your mother is sick. Having lost both parents recently, I can't imagine how much harder it would've been if I hadn't been there. I really hope you can find a way to go.