I see that you live in Canada
You might want to consider changing to a more gentle and longer acting insulin than Canisulin.....it's mostly for dogs (thus the "cani" prefix) but a lot of vets use it because they are used to using it (they see more diabetic dogs than cats)
It tends to drop the blood glucose fast and early in the cycle and then wear off before the next shot time.
Lantus and Levemir are both human insulins available at any pharmacy and are both much gentler and longer acting. In Canada, they're over the counter too! You just have to ask for them! Here in the US, we have to have a script
We also have a spreadsheet we all use here to keep track of the numbers....It's a very valuable tool in our toolbox and we really depend on it.
Here are the
Instructions for setting up the FDMB spreadsheet....since you're in Canada, you'd use the "World" spreadsheet using a human meter (I know you have a One Touch Verio IQ meter)
Another key to getting the best results possible (On any insulin) is reducing the amount of carbs the cat is eating. A lot of our Canadian members feed the Fancy Feast "Pates" that are all low carb and fine for diabetics (but there are other foods available too)
As long as you're able to test, you can start transitioning off the higher carb foods and on to a low carb food.....it's just like human diabetics....if they keep eating potato chips, they're never going to get much better and will require larger amounts of medication......the one big difference in cats though is that they have the unique ability to have their pancreas heal and resume working again!! But to give it the best chance at healing, you need to restrict the workload (less carbs) and use the insulin to give the pancreas a "break" to do it's healing
Not all cats can go into remission, but a good low carb diet and a good insulin will give you the best chances!!