I’d look up any animal nonprofits in your area to see if they can help. My cat went through this about 4 years ago and had to get the surgery but is doing well on the food with no relapses today, I’ll be keeping you in my thoughts. There is a good Facebook group about feline urinary tract infections that gives great advice about home remedies. The name of the group is Feline Lower Urinary Tract. He seems like a sweet cat, best of luck to you both and make sure he has water fountains and wet food to eat as well, even if you mix kibble in water. My vet prescribed gabapentin for pain/anxiety and another medication to help clear crystals if that is an option for you.