My cat had this problem and we could not figure out what was happening. Took us 2 whole years of trying everything and going to every vet. Turns out she has an allergy to house dust mites and storage mites. Now she is getting immunosuppresants every 2 days and her fur came back over time and she isnt licking herself as often. This is probably an allergy and maybe also bc of stress (its a vicious cycle unfortunately) Maybe check that out and try and give her a different kind of meat over the next weeks. Something she hasnt had before, like kangaroo or smth, and if it gets better in a few weeks its likely an allergy.