As a sufferer of illness anxiety disorder, what you’re describing sounds a lot like the thought processes I went through before seeking therapy for it.
You’ve described very little evidence indicating you have diabetes, but a ton of evidence indicating you have illness anxiety disorder. I am not a doctor and cannot diagnose you, but my suggestion is to talk to a professional who can.
A Ford Expedition from a car rental place. It felt like driving around a ten ton brick through molasses. It was the least responsive and awkward shit box I’ve ever had the displeasure of piloting. It was so bad I literally drove to the nearest rental place to exchange it for a smaller car.