Mr. Dumpling is In The Hospital

This is Mr. Dumpling. He is my best friend and my therapy animal (to help with major depression and anxiety). I got him after I lost my job and had to leave school 3 years ago. He has been by my side through several life changes and moves, including to Colorado where we now live as I try grad school again!
For the past month, my sweet Dumpling has not been eating as much, been throwing up, and having diarrhea. I've been to the vet at least 3 times for this. Yesterday we got the blood work back, and found out Mr. Dumpling has stage II Kidney Disease. 
The vet is mostly concerned right now with getting him to start eating normally again, and then we will worry about the kidney issues. Thankfully he said we caught it fairly early as most cats reach stages 3 or 4 before they are diagnosed. 
As I mentioned, I am in school full time and can only work about 20 hours a week. I make less than $1100 a month. My rent in this mold and bug-infested apartment is $950 (but that's another story).  Currently I am surviving off student loans to eat, have electricity, and internet to do my school and work from home. However, I did not budget for hundreds of dollars of cat expenses when I took my loans. I only took enough to last *me* through the semester.
I want to do whatever it takes to keep my best buddy happy and healthy, but I really cannot afford even the bills I already have. I have been putting them on my credit card since I don't have the money to pay. I worry that in the future he will need more expensive treatments.
For now, we have a follow-up appointment in a couple weeks. Every visit is $70, and I have spent over $1200 so far between the blood work, the urine testing, the special food, the medicine, and the exams. I can't keep doing this, but I have to for Mr. Dumpling. 
Anything you can give would be so, so appreciated. I can't thank you enough.