That looks huge, you must be so frustrated. I found this article about natural remedies, worth a read if nothing else. Everything I have read says it is a slow process to recovery to hang on there.
Natural Treatments For Feline Pillow Foot (Feline Plasma Cell Pododermatitis)
I agree with the previous posts. Its a relatively easy and quick operation for a male cat. Mine was home in a couple of hours, no cone needed and no stitches or meds needed. Phone around other vets and get prices and procedures.
My cats have stinkies. I bought them about 3 years ago and the cats still love them. As far are treats are concerned, I give them a few of their dry food bits, throw them across the room and the cats run after them making a bit of a game out of it.
Try not turning it on for a week or more, just fill with water and give her a chance to get used to it. Once she is used to seeing it and has no fear, turn it on and hopefully she will start to use it.