Cello's vet bills

My kitten, Cello, was something of a rescue cat. She lived in a yard with no shelter, and was infested with flees that almost killed her. Even though she was sick for the first two weeks we got her, she eventually recovered, and became the light of my life. As someone who struggles with depression, having her give me love, sleep with me, and cuddle with me regularly has really helped reduce my nightmares and helped me pull through college.
Now, four months later, she's deathly sick-- the vet isn't sure what's going on. His best guess is an ear infection caused by bacteria, but he can't be sure without a $600 test. Everytime we take her in, it's another $50 for them to check on her. They expect us to take her in 3 times a week, and it's already taking it's toll. Our family has very little money, and we can hardly afford to feed ourselves, let alone save my cat. We've put in as much money as we can, but it's quickly becoming too much. As much as I would love to get her tested, it's out of the question with our funds.
If you could spare something for her, it would be a miracle. Thank you for at least reading this far, if anything. I want to save my little girl, and hopefully a test to diagnose her would give her a fighting chance.