Help Me Take My Cat To The Vet

This is my cat Kiki . She's 15 years old. I was raised along side her, and I know something's wrong. She won't meow or purr or react in any way when I interact with her. She seems very lethargic and spacey. I don't remember the last time she ate. I called the vet and they say to bring her in right away, but emergency walk ins are $200, plus medication/treatment costs. I'm currently on disability, and can hardly take care of bills and groceries, let alone take one of my cats to the vet. I think she's dying, but I have to find out if there's anything I can do to help her. Please, donate whatever you can, every dollar counts. Please help me help Kiki.