Well i hope everything turn's out for the best i just brought a diabetic 6 year old male into my home yesterday and he's on 4 units in the morning and 3 unit's at night but he seem's to be doing really well except that he is 14 pounds and is starting to go blind. The injection's i don't think really hurt but there is also pill's you can give your cat for diabeties but i think injections are alot better all i have done when he need's his injections is pull up some skin and to make sure you don't hit a vein or muscle,
Here are a couple of link's i have gotten.
I am also still trying to find some other good sites on feline diabeties. I hope you don't put him down because of it as i was telling a friend of mine that i might be getting my new diabetic cat a couple days ago and she said that he should of been put down.