A cat that isn't eating is a medical emergency. Does your vet know she hasn't been eating for so long?
LP is right--you need to find another vet or emergency vet who will see your cat right away!
"We are--each of us--dying; it's how we live in the meantime that makes the difference."
"It's not what you gather, but what you scatter that tells what kind of life you have lived!"
"Be kinder than necessary, for everyone you meet is fighting some kind of battle."