I'm so sorry you didn't receive an earlier answer. Different experts are online at various times and I recently logged in and was notified of your question.
If your cat is not eating and can't keep anything down, she may have ingested something she shouldn't have, she may have an intestinal infection, she may feel nauseated or there may be something else wrong. If her stomach is empty, she's producing excess stomach acid which can cause nausea. You can give her 1/4 of a 10mg. Pepcid AC (Famotidine) tablet in a teaspoon of plain jarred baby food chicken containing NO onion or garlic products--Beechnut Stage 1 Chicken is a good one. You can crush the pill first and it should 'melt' into the baby food. Hopefully, she will keep the small amount of food and the pill, down. You can try the 1/4 pill uncrushed, too. It's a very small pill so, 1/4 is tiny. You can also try a smooth paté, canned cat food that she's used to.
If she continues not eating and vomiting,and also not drinking, she needs to be seen by a vet to get a diagnosis and treatment. She may be dehydrated and needs fluids I.V. or under the skin. She can be given an anti-emetic (anti-nausea) injection, which is much easier with a vomiting cat.
When a cat doesn't eat, even for a short amount of time, she can develop a serious liver problem called hepatic lipidosis, and if she's not drinking, dehydration is also of great concern, so that's why it's important that she's evaluated in person by a vet asap.
I understand fully, that she freaks out going to the vet and at the vet, so, a good idea for you, would be having a housecall, mobile or ER vet come to your home. You can find if there are any near you, by plugging your zipcode into this site:
I hope all will be well with your furry girl, once she's seen by the vet and treated!
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