My cat has Fever and does not eat

I have bought a cat from a pet shop for three month now. She is about 7 month old today. She has not been eating well for the past three weeks. about two weeks ago I took her to a vet and did several urine and blood tests. The vet found out that she has the corono virus in her blood and said she might have FIP. As far as I have researched she does not show any distinct symptom of the two types of FIP.
Her current symptoms are:
-Drinks loads of water (this is not specified for any type of FIP)
-Does not eat food well and only eats a little
-Does not play
-Has high fever of 40 Degree's Celsius
and everything else is normal about her.
I have been giving her antibiotics which has not changed anything much. I am thinking maybe she has another condition and this could be something other than FIP.
I would really appreciate any help as my wife is devastated by her illness and dont have clue on what to do. Can anyone help me with this condition?!

You really have to work with your Vet on this. It's a very good sign that she will eat anything. It is very dangerous for cats to not eat, they can develop fatty liver disease. Her temperature IS high, did the Vet not dispense any medication for fever? You can give a cat aspirin but never, never, never without your Vet's say so as a very small amount can be deadly for cats. However it does help bring down a fever. The antibiotic will help but I have had both dispensed at the same time for two of my humane society cats.

I'm sorry, I hope she recovers. So many ailments have overlapping symptoms. The only way to get through this is with your Vet's help. FIP testing is unreliable, you can get false negatives and false positives. The positives show up sometimes because cats can carry FIP and not show symptoms, like AIDS.