FLUDT post catheter behaviour

Hi guys. I took my 3 year old cat to the vet 5 days ago because of a blockage in his urethra. They took him and immediately put a catheter in. 2 days later they sent him home with antibiotics, prescription wet food and a pain medicine to administer orally. He was diagnosed with FLUDT

My cat hasn't been peeing fully, just little spots in the litter here and there. I did find a few bigger puddles on the floor though. He seems to be very lethargic and obviously sore on his stomach. This morning he threw up on the floor but seemed fine otherwise. He is eating his wet food, and I added water to it to ensure he is still getting enough water.

I'm just wondering if anyone else has had these symptoms after getting back from hospital. The vets said the blockage was very minimal and the blood tests/electrolyte test was all good. My cat is my baby and I am a ball of anxiety.

Have you called the vet and described the symptoms?  He may need to be taken back in.  FLUDT is difficult to deal with since they can't tell us anything, and it could be another blockage that they didn't see or just bladder spasms--and those will make him miserable without meds for it. 

I've been through this with one kitty, I felt so helpless because I couldn't tell what was going on.  Sending you hugs