I cannot stress this enough: WHEN YOUR CAT HAS MEDICAL PROBLEMS, TAKE THE
CAT TO A VET!

Few of us have medical traing, and those of us who do would not give
medical advice without physically examining the cat.

The best you can hope for is anecdotal stories of similar ailments and
what worked for THAT CAT.

Please have a vet look at your cat.

Hugs and Purrs,
Mark

Mark has given excellent advice.  All of us on this group love cats (that's
why we're here), but it simply isn't possible to diagnose a specific problem
from "long distance."  Moreover, the you have described a problem that has
existed for several weeks, so it is long past the time when your cat should
have had a medical evaluation.  Please make an appointment immediately!
(And then please check back and give us an update.)

MaryL

PICK UP THE PHONE CALL THE VET

there are so many possibilities of what could be wrong from allergies down
to parasite to behavioral

Let us know when you do see the vet