aww Kitten...im sorry
I hate this disease.
I hope you can get some rest, and perhaps it will turn out to be a mini event due to being over tired from working the extra shift. I find that being over tired, overstressed, or overheated throw me into a funky day.
Feel better quick
I usually try to do quiet things like watch a movie, or listen to a book on tape, or just do quiet things around the house. I try to not push it, and will sneak in some chocolate or ice cream to make my comfort level rise. Comfort eating everyday isnt a good thing, but a treat now and again helps. Try to not beat yourself up. Get some rest.