K.S.
Drink lots of fluids and stay cool. It's been very hot and if you don't keep hydrated, your body will give priority to perspiration to keep your core temperature cool rather than using that fluid to make milk.
It could also be time to start weaning your daughter. Continue to feed and to pump and see if your supply returns to normal levels. Don't be afraid to supplement with juice, water, or formula, but she is coming up closely on the time when she will be given the go ahead to drink 2% milk.
Cats lose their appetites when they have an upper respiratory problem because their sense of smell is so integral to their appetite. Kids are very similar in that respect. Antibiotics can give stuff a metallic taste or generally decrease the appetite.