Head swaying

My cat Bobby started swaying his head back and forth slowly last night after he wounded underneath his ear by scratching too hard. I noticed that he has a little blue bubble right on the inside of his ear that was not there 3 months ago. I am very concerned for his well being.

Hello - it sounds to be as though Bobby could be struggling to balance, or could be expriencing relatively severe confusion or pain.  Your duty vet may want to triage this case immediately in case an emergency appointment is required.  From the little that I understand, this sounds to be a sensible course of action.