[gremlin]

I think you should take her to a second vet for a second opinion, get x-rays if you can afford it, then you can make sure that nothing is wrong inside of her... just to be sure.
My dog began to suddenly vomit every day, then she refused food. We changed her brand of food, she refused, tried cat food and she still refused. She even refused treats and human food. She also excessively drank water. She also became slightly anti-social and spent most of her time on the cold kitchen floor sleeping.

Is your kitten doing any of this?