Take a deep breath and relax. You can do this but all kittys are different. Is this a cat that enjoys lying on her back? It looks that way from the picture you have put up. Mine does. Have a read of my thread
http://www.felinediabetes.com/FDMB/threads/newly-diagnosed-in-the-uk.155984/ where I am running a diary of my experiences in the hope it will help others as well as getting some great advice from the more experienced folk on here. I have had to adapt to the cat. She was fine at first getting her shots when she was eating as she was so hungry she didn't care - her focus was her food. As the insulin has kicked in she doesn't want to be messed with when eating but when full and happy and away from her food bowl she is accepting the shot more easily if it is injected away from her scruff. I only grasp her flesh to make the tent rather than trying to hold her. Sounds as though your kitty is getting annoyed at being messed with so the less messing the better. She has to learn to associate treats and love with her shots and blood tests. I tried taking blood from her ear and she made it clear she didn't like it and I found it really difficult.
Try this for getting blood from the paws which is what I am doing and seems to be working.
First set out your equipment. A large towel on the floor, some alcohol gel or wipes - something to clean the paws. Some vaseline or neosporin, whichever you have to hand. Cotton wool wipes. An old sock with a handful of rice in it and then knotted to make a little bag. Load up the lancet machine. Push the strip almost into the meter but not far enough to activate it. Make sure you have spare strips to hand in case the blood doesn't go onto it the first time. Everything should be in easy reach for when you sit cross legged on the towel with the cat. Warm the sock in the microwave for 30 seconds, throw it down on the towel then go get the cat. Have good light to work by.
Sit cross legged on the floor, cradle the cat between your legs and on her back, and grasp one of the back paws, apply a tiny blob of alcohol gel and rub in well.
Place the warm sock over the pads and while the foot is warming up make a big fuss of the cat so she associates this with getting good attention.
Once the pads are warm place the lancet machine firmly onto the rear large pad, I have the alphatrak set on 4 which goes nicely into the pad. Press the button and hold for 2-3 seconds before withdrawing and as you put the lancet down push the strip all the way into the meter.
Gently squeeze the paw pad until you see a little blob of blood, the meter should now be ready to read.
Hold the very edge or end (depending on which meter you use) of the test strip onto the top of the blob and it sucks it up and beeps, put the meter down.
Press gently on the paw pad for several seconds with the cotton wool pad to prevent bruising, then rub a small amount of vaseline onto the pad whilst making a fuss of the cat.
By this time the meter should have given you a reading.
Let go of the cat and reward her with a food treat and more fussing. Using this method seems pretty painless for her, her ears flick as the lancet goes in but I'm not sure if it is the noise or the needle. I have had some failures and had to go in a second time to get the blood but I think I didn't leave the sock on long enough.
The videos make it all look very easy but they are made by people who have been doing this a long time and seem to have very docile cats!