Hi Carol, I am really sorry to hear about your kitty getting diabetes and the difficulties you’re having. One of my own cats has diabetes, but I have been very fortunate that giving him injections has not been stressful. I do them while he eats and it provides an excellent distraction. Having a cat that does not like to be handled or is easily distracted from eating by close contact, noise etc., makes it very difficult to do insulin injections in a low stress way, especially when the injection itself is not really what is causing the cat distress. I’m sure having to fish your kitty out from under the bed is not helping his stress levels.
Cats can feel anxiety and stress in people, so you may need to try another time where you are both more relaxed. What’s most important about insulin injections is that a full meal has been eaten. You can give the injection shortly after. Some cats after eating, go to find a comfortable place to rest. You may try doing the injection more at that time if your cat has now associated the food bowl with stress. Maybe there is a very high value treat you can use separately from the meal.
Or if your cat is always going to be scared of handling or injections (but at least is not aggressive or at risk of causing you harm). You can try some gentle restraint methods with a blanket or grooming sling, especially if someone else at home can help. While the injection may still be stressful, this could help separate the association from mealtimes. After the injection, giving some high value reward can also be helpful to desensitize a cat to something stressful.