turns out we do indeed have a diabetic cat. For the last week, I've been giving him an insulin shot every morning. It's not as hard as I thought it would be. And he's back to his normal shithead self.
Except he has poodle paws in front from where they shaved his legs (rofl).
With any luck he will be one of those cats that, at some point, has spontaneous remission from diabetes. That would be great.