My Injured Cat Coco Needs Help

Today I found out my family's cat Coco was horribly bitten by another cat. We took her to the vet and found the damage to her rear quarters to be extensive. She is undergoing surgery tonight. I paid $750 using a credit card, and I need to pay another $250 tomorrow. I am already in debt, and I don't know how I'm going to make these payments! Any help would be wonderful! Coco is a sweet 10 yr old black tabby. We love her as a member of our family, and will do anything to keep her alive and well.