12 yr old cat circling, lost weight, confusion?

My 12 yr old cat has recently had problems eating, started out as not being able to crunch dry food. She started circling every few steps, always clockwise. Now she sits in one position, acts confused, walks with her head down, has to be reminded to eat her wet food. Vet did bloodwork and dental cleaning, everything looked ok. He did find a slight swelling in her right ear, cleaned out lots of wax and pus, but couldn't find bacteria under the microscope. After recovering from ear procedure (leaned to left, fell down when shaking her head), she went back to circling, even when going up/down stairs. Just seems to sit in one place all day. Acts hungry, but it's a task to get her to eat more than a little bit of food since she licks at it rather than taking bites. Overall, she seems confused and dispondent. Vet is testing for toxoplasmosis, but as she's an indoor kitty I'm not expecting this to turn up positive. Any ideas?