Welcome to the FDMB! You're in the best place you never wanted to be!
Diabetes is not a death sentence and with proper care, your Scout can live a long and healthy life. It's great that you have a cat sitter that will help you! Giving the shots is really simple and most cats never even notice them.
Need some more information from you. What food is Scout eating? A diabetic cat needs to eat a low carb canned or raw diet that's less than 10% carbs. Most of us feed our own cats Fancy Feast Classics, Friskies pates or 9-Lives ground but
HERE is a food chart that has a lot of common foods and their nutritional breakdown. Just make sure they're under 10% carbs.
Have you started insulin yet? If so, what kind? Some are much better than others. The recommended insulin's are Lantus, Basaglar, Levemir and ProZinc but a lot of vets are still prescribing Vetsulin/Caninsulin which is a fine insulin....for dogs. In cats it tends to hit hard and fast and then wear off before the next shot is due.
If you have started insulin, it's important that if Scout isn't already eating a low carb diet than when you do the diet change, you do it slowly and when you can home test. Reducing the carbs in the diet can drastically reduce the need for insulin. Some lucky cats can even be diet controlled without ever having to be on insulin, but most need it at least for a short time.
It will be important for you to learn to home test. If this were a child that was diabetic, you'd be told to test before every shot...it should be the same for our furkids! Otherwise we won't know if it's safe to give insulin at all! By testing in between the shots, you also learn how he's responding to treatment. I know it sounds like a lot right now, but once you get your routine down, it's no more disruptive to your life than brushing your teeth. I could Test/Feed/Shoot China in about 5 minutes and then tests that I'd do between the shots took about 60-90 seconds.
HERE is a link to the signature, hypo kit and other useful information
https://felinediabetes.com/FDMB/threads/new-how-you-can-help-us-help-you.216696/
You can do this!!!