Do you have any sick leave left, that you could take tomorrow off and just make it a long weekend of nursing, nursing, and more nursing, preferably in bed with lots of skin to skin contact? Try as much as possible not to be up and about - no housecleaning or catching up, have someone bring you food in bed or else make as little effort as possible to eat.
Drink lots and lots of water, or, since you haven't been eating and drinking much, soups and broths (as long as they're low sodium), smoothies, fruits like oranges and mangos, etc. Really get some food and hydration into you, but if you have to make it yourself, make it as simple as possible, don't work!
Do you have a health food store nearby? If so, pick up some fenugreek capsules, blessed thistle (if they have them), and if no blessed thistle then nettles and alfalfa capsules. Take 3 to 4 of each, 3 times a day (you'll start smelling like maple syrup from the fenugreek, which means you're taking enough).
And remember that a) babies are much better at emptying your breasts than the pump is, so that's not a great indicator of supply, and b) your breasts can feel "empty" and still produce milk. So you may have more, and your daughter can get more, than you think.
Have you been supplementing? What has dd been eating if she hasn't been nursing? She needs to eat, but supplementation may lead you into a downward spiral of not nursing, so offer her the breast as much as possible.
I hope you feel better!