sick kittens

ugh! on friday i got a call from the program director of the rescue group i am fostering for- she told me i "forgot" one of the kittens at the shelter! - i did not forget- i got the whole sibling group, but she had wanted me to also get another kitten who i knew nothing about, and niether did the shelter. so i went to pick little Blue up. He is a 4 weeks older than the other kittens but the same weight. he has SEVERE diarreah and was/is severely dehydrated. to keep him alive i have been syringe feeding him sugar water mixed with high calorie kitten food. he is on three meds and now the other kittens are all coming down with a cold, and will have to get on meds.the kitten with the runs is pooping EVERYWHERE and i am cleaning the room multiple times a day. i have to wake up at night to give him the sugar water, just so he makes it through the night...i am SO tired. i signed up for healthy kittens. these kittens (especially one of them) need round the clock vet care. i am so worried one is going to die and i am going to have a kitten death on my hands...