Hon, that's not normal fog. *big hugs* Look at all the stuff you have going on - no wonder you're a little scatterbrained!
I'm sorry to hear about your husband - that's terrible! I'm pretty sure mine has gallstones, and whenever he gets a little attack I panic for a good day or two and can't focus on a darn thing. I can't imagine what'd happen to me if he were seriously ill, like, in the hospital or facing something major like yours may be. =( I hope your dude gets better soon and that it's NOT something major!
In the meantime... can you do some small stuff for yourself? Doesn't have to be huge, but like... go get a pedicure or a half-hour massage or even do a totally-bad-for-you lunch with a friend? Anything to kill the stress for a little bit and let yourself off the hook!
It's probably your extreme stress level combined with the fibro fog.
Don't be afraid to go ask for an anti-anxiety pill if you need it. Lorazepam is a good one, doesn't knock you out, and it'll just bring you down a notch so you can really function. I wound up taking it about once a week (as needed) after I learned about my dad's illness being so severe. It -did- help me get that focus back.