Jen, I'm sorry that you're feeling so stressed but I sure can relate to what you're going through.
When I brought Storm home after his PU surgery, he was peeing quite well for the first day because he had a lot fluids in him. On Monday though I panicked because he didn't seem to be drinking anything and he wasn't peeing. I tried to feel his bladder to see if it was full or not but I couldn't feel anything. I had to end up bringing him to my vet and it turned out that his bladder wasn't very full. Even though the vet tried to show me how to palpate his bladder, I still couldn't feel anything.
Many more prayers and positive thoughts are being sent your way. Please take care.