Welcome to FDMB. You have found a place of resources and support to learn about feline diabetes and treatment. There are three main components of effective diabetic treatment: proper diet, insulin therapy and blood sugar testing. We recommend a low carb wet diet. The "prescription" diets are not prescription at all, and for the most part much too high in carbohydrates and very expensive. It's like giving waffles and syrup for breakfast to a human diabetic. There are good alternatives that are much better for Pooky. Feeding a low carb diet can also lower blood sugar, which could decrease the need for higher doses of insulin.
Home testing the blood sugar is going to let you know, real time, how the insulin is affecting Pooky. Human diabetics test their blood sugar before injections to be sure it is safe to do so, and during the cycle between injections. We do the same with our cats. It saves you money at the vet and stress for your cat which can raise the blood sugar. Testing is one of the best tools you have to help prevent a hypoglycemic event (very low blood sugar) which can be life threatening. It's dangerous to "shoot blind" and you should know what the insulin increases are doing to the blood sugar.
Tell us where you are so that we can give you some information on low carb food, and testing supplies. We can help you learn to test and get Pooky feeling better and on his way back to better health.
There is a wealth of information here to read and we can help you begin to learn the basics and then help with further steps along the way.