help my blind baby get surgery

My baby boy Leo has blood in his urine and is barely peeing, which is deadly for male cats. I've spent over $500 in vet fees for the vet to not even diagnose him officially and don't have the money for any more testing, then the surgery after. I was roughly quoted $1000 for lab tests and possibly $3-4000 in surgery/medication. Leo truly is the sweetest cat in the world and anything at all will help.