Welcome to FDMB.
We all have been where you are right now, scared and probably overwhelmed. But like everyone has told you, it is not difficult caring for a diabetic cat. With the help of everyone on this board, you will learn tips to help you develop the routine that works best for you.
Read over the information on this site. I realize there is a lot, but concentrate on the posts for hometesting, food, insulin and hypoglycemia first.
1) Hometesting means testing your cat's glucose levels at home before EVERY shot. This is the only accurate way to determine if the insulin dose is working, if you need to adjust the dose and also if it is safe to give the shot. Some vets try to discourage it, so don't worry if your vet is in that group. Just remember, you are the person who is ultimately responsible for your cat's care - if your cat was your child, would you give insulin without knowing it is safe?
2) Food - Your vet may try to prescribe prescription food, you don't need it. Many of the prescriptions foods are high in carbs anyway. Most of us feed regular canned food such as Friskies, Fancy Feast and Special Kitty. You do want to stop feeding dry if you currently are feeding it to your cat. And if you have more than one cat, this means the same for all of them. Dry food is high in carbs. It is not unusual that with just a diet change, you may be able to stop giving insulin - your cat's diabetes will be diet controlled. It does not happen to all cats, but many cats are able to become diet controlled.
3) Insulin - There are many types of insulins, but we recommend long acting insulins that have been very successful in treating feline diabetes. These are Lantus (Glargine) Levemir, Prozinc and PZI. Avoid short acting insulins such as Humulin and Vetsulin - they wear off quickly. You also want to start low and slow. This means only start with 1 unit and wait until at least one to two weeks between dose changes before determining if you need to increase it. If you do need to increase the dose, it is only by 1/4 to 1/2 units at a time. Too much insulin can cause hypoglycemia. Also, do not give insulin until AFTER your cat has eaten.
4) Hypoglycemia - this means that your cat's glucose levels have dropped to low. This is usually caused by either giving to much insulin or your cat did not eat after getting the dose. By using hometesting, low carb foods and proper insulin dosing, this usually can be avoided. This is why we stress the importance of each of the items listed above. But, you do need to be aware of the symptoms and also what to do if it does happen. Not knowing can be deadly for your cat.
Ask any and all questions you may have, even if you think they may be silly or stupid. Like I said, we have all been in the place you are right now and we are here to help you.