Just Breathe, diabetes is about the easiest thing a kitty can be dxed with as far as treating. Once you learn how to give shots (which isn't tough, most cats don't even notice) and home test ( again super easy once you get the hang of it). Tweak the diet a little bit it is so easy to deal with.
I have 11 cats only one of which is diabetic. When I first found this board it was with my very first sugarcat Muse, at the time I had a lousy vet, and by the time we finally discovered what was wrong with Muse, she had so many other health problems she passed away in June of last year (from cancer not diabetes). But with what I learned from these fantastic folks here, when Max came up for adoption, my husband and I jumped at the chance to adopt him. I knew ahead of time he was a diabetic and like your guy was 10 years young. Now with 10 other cats I certainly didn't need another one, so if diabetes wasn't a very easy thing to treat I wouldn't have set myself up for the heartbreak of adopting another one. I couldn't be more please that we did adopt Max, he is a wonderful kitty and a treasured member of our furry family. He is one of the lucky ones that with about 2 weeks on Lantus and a diet change from cheap dry food to a low carb/high protein canned diet he went into remission where he has stayed now for the last 3 months. He has gained back all the weight that he lost while he was sick and not being treated, he plays with my 9 month old kittens, and if you didn't know he was a sugarcat you would never guess it.
We feed all 11 cats exactly what we feed our diabetic, just good old fashioned Friskies pate flavors that are 10% carbs or less. Even my non-diabetics have improved in overall health on this diet switch. Yes, it is a little more expensive on the food, but it more than makes up for what we aren't spending at the vet.
I like many here use just a regular human meter, to test his blood sugar, we just prick the edge of their ear to get the blood sample. Now with Max since he is in remission I don't have to test him as often as I did when he was on insulin, but I do still test him a couple times of month to make sure he stays in remission. But even if he hadn't gone into remission, those 2 little shots a day are no big deal. To test, feed and give insulin added about 5 minutes to my day, no biggie at all.
But since sometimes a picture is better than a thousand words, this is a video that I made of some of our kitties that were adopted as diabetics, when their previous owners were going to have them put to sleep. But now that you have found us, we can help you help your furry baby, and we will be here to hold your hand and paw every step of the way.
Mel, Max & The Fur Gang