I knew someone who had a mildly diabetic cat that was put on the "Atkins diet for cats" (basically pure meat/fat) and the cat lost weight and went into remission. As in humans, diabetes can often be controlled by diet. It would be much easier to feed different food. Ask your vet about prescription diets. You may also want to research and ask your vet about the bones and raw food diet.

Good luck and welcome! Pet your precious kitty for me.