Took her to the vet again this Saturday. She got a shot of cortisone to help with the fever and irritation in her throat, and has improved dramatically. The second vet noted her throat was an angry red, indicating she must have ingested something caustic that burned her throat. I still have no idea what that might be. The friends who she stayed with said the only thing she got into was paint thinner, so we're all at a loss as to what it could be.
In any case, her appetite came back and she now will get up to greet me when I walk in the door.
Also, thanks for the vet recommendation. I go to Laurel Pet Hospital in West Hollywood and am really happy with them. They could have recommended expensive blood tests and x-rays right away but they didn't. And Bean's getting better so something went right.