He wasn't getting any better from his UTI in fact he was getting worse and started having pee in his blood. So back to the vet today.
I decided to try and get a urine sample this time and they took it and said he has crystals. He's now on gross Hill's food for a month to try and fix it.
It's so sad to see him just sitting in the litter box for up to 20 minutes just straining.