Avocados vet bills

My cat Avocado is six years old, and he's never had health problems before until now. He is struggling with crystals in his urine and has a possible obstruction, and the vet told me that it would be around $3000 to fix that, flush him out and put a catheter in, and keep him overnight for observation. I, unfortunately, don't make enough money to pay $3000 upfront. This is an emergency and needs to be fixed as soon as possible if anybody can help, I would appreciate it. He's the most important thing to me. He's been with me through so much and I don't know how I'll keep going without him. Please anything helps. I understand if you don't have the money. Hence why I'm here but if you can share that would be just as important.