I'm sorry that Mick is diabetic, but vets are seeing more and more of it, so he's not alone. I'm sure your vet has given you instructions on managing the disease so there's probably not a lot that we can add.
Is Mick overweight? If so, it's important that he shed some weight. My cat used to love to chase little balls of crumpled up paper. She'd retrieve it and drop it near me, and I'd throw it again. She'd do this until she got tuckered out. If Mick needs to lose some weight, perhaps that's a game that will help.
I would assume that your vet has Mick on a prescription diet. If not, I know that Merrick makes a variety of very well formulated canned foods, some of which are low glycemic. They have a gold "Low Glycemic" burst on the label so they're easy to identify.
Best wishes in managing Mick's diabetes. You're a good cat Mom for taking on the responsibility, and Mick is fortunate to have you. Regards, Bob