Help My Cat Rose Get Well Soon

Rose is my cat who I've had since she was just a few months old, she's a little over 5 now. We had to take her to the vet to drain an abscess on her neck, but the next day she wasn't feeling any better. Breathing heavy, still very lethargic, wouldn't eat and barely drank any water. I took her back to the vet ER and they told me she has pneumonia. She needs oxygen, IV fluids, and IV antibiotics, potentially more care depending on how she does. She's in the hospital now, but we can't afford all the care she needs. I'm desparate to help my girl. I just want her better.