Do not feel bad. I am in the same boat.
I have watched numerous videos showing how they cut it but I've noticed that in each video, the animal is biting, crabbing, or abundantly moving around.
I have the Silent Wheel with the sandpaper and most recently a trimmer from Pocket Pets.
I am doing better with the trimmer and I can usually get 1 paw down before I get them so nervous that I get nervous. Even Serena, my biter, was happy chewing on a dried chicken neck that she didn't mind.
I think the key is to find something that works for you (pet trimmer in my case), something that can keep them occupied (dried chicken neck), and patience with courage.
I say the latter as I more confident last night doing the nails and more calmer that the girls were getting too aggitated (I stopped and put them back in the cage if I felt they were getting stressed out)
You got this