No, you are NOT an idiot who causes her cat pain! You are a very concerned, loving and responsible cat-mama who is doing her best to give her cat the best health and quality of life she can. Let us hear no more of this self-berating! Give yourself a big pat on the back for having the patience, love and bravery to do this every day. Lots of people would have put it all in the too-hard-basket, got someone else to do it, paid the vet to do it, or abandoned the cat. (No-one on this forum, of course). Some days it goes better than others, your cat understands this, she's so grateful to you for all the love and support you are showing her. It's like everything else in life, sometimes you can back into that parking slot in one, the right distance from the kerb, perfectly parallel blah-di-blah, another day it'll take you three tries and the car is still crooked and you need a bus to take you to the kerb! Some days are diamonds, some days are stones....