please help!!

my cat has been ill for the last week or so. it started with some vomiting (which i thought was normal), and then about 3 days later i noticed she had become very lathargic. i took her to the vet on monday and she had a temp of 105.9!! they gave her fluids to bring the fever down, and gave her a shot of cortisone & antibiotics. tuesday she felt better, and her fever seemed to be gone. this mornig she started with the lathargy again & i took her back to the vet, and she had a fever of 105.2. they gave her more fluids, antibiotics, and drew some blood. they didnt tell me anything about the blood sample except that she had a virus, and not a bacterial infection. her fever is gone now, but she does not seem to be perking up. her symptoms are/ were lathargy, high fever, a little vomiting in the beginning, weepy eyes, and loss of appetite. she is only four years old, and i don't know why she is having so much trouble. the doctor keeps trying to convince me that it's just a flu, and she has been vaccinated against all required viruses for kenneling purposes (she was kenneled in may). please someone give me some advise, some good news, because i am panicking badly & she is miserable. she has not had any vomiting since the fever started, and shows no signs of having resperatory ailments. any advice is good, as i am going crazy right now!!! thanks.

is she still at the vets? I would suggest if she is home, you take her back to the vet tomorrow so they can monitor her and give her fluids if her fever spikes again. Either that or ask the vet if he can show you how to give her fluids. The high fever would be the most concerning as cats dehydrate very quickly. The fever will sap her body's energy so she will be lethargic. Keep her in a dark room and keep her quiet and push fluids on her. Pedialyte is best, if you have to syringe water down her, do it slowly or you could flood her lungs.

she is at home. do you have any idea what this could be?! i have been reading about FIP and i am really scared. she is an only cat and only goes outside to sit on the patio, she never goes very far. she is a little overweight, and her glucose levels were pretty high. could it be pancreitis? please help!!

I really don't know what it could be, as there are so many things it could be. You did the right thing getting her to the vet and getting bloodwork done on her. You will make yourself crazy with worry by projecting and starting that thought proces of what if it is_______.
Your vet should answers for you fairly quickly when the blood work comes back. I know it is hard, but try not and think what it could be, wait until they know what it is then work from there. Sometimes it just turns out to be "fever of unknown origin" and the cat is fine in a few days, but again, wait to find out. Try not to worry and just see to the cat's comfort. Dark quiet rooms are best, cats can regenerate when they feel puny.