poor little cat. he must be in agony. please take him to another vet asap. your vet is not sorting the problem. you need fresh eyes. today preferably.
cats mask pain. so dont thibk “he doesn’t seem to be in pain”. he absolutely IS in pain. We all know how sore a UTI is.
ps crystals are sadly common in cats. more dangerous in males. you must make sure he does pee. if he stops peeing it could be because he has a crystal blocking his pee tube. this is serious and he must be seen the same day as it can be fatal.
Have they tested for infection? My cat never showed infection but we sent off a pee sample anyway £150, to be cultured in a lab and it showed up what uti infection it was and what antibiotic should be used to treat it. i needed a ten day course, at about £30 a week, as my cat had it for months. it kept coming back. it was awful. i think you could be in the same boat.
the poor cat won’t want to pee everywhere. it’s the pain. poor thing. it’s not his fault. it must be agony. Imagine peeing out jaggy edged crystals daily. agony.
what can you do at home to make him less stressed? do you have feliway plug ins? they release calm hormone smells and really help. i used the (pets at home or pet smart or whatever it’s called now) cat one as it was cheaper. leave it in 24 hours a day.
feed wet food. a water fountain can encourage drinking as they like running water. as others have said try non fish flavour wet food.
you cannot just give up the cat. hes your responsibility. just like a child. his whole world is you. you are his everything. hes family now.
you just need to get on with fixing him. youre doing the right thing for the wee man taking him to a new vet.
And don’t get any more pets in future if life is too busy or expensive. vet fees are something we don’t think about but i learned the hard way that pets can cost practically nothing or thousands per year. it’s just your luck. i have none now. not because i dont want one,but because i cannot afford vet fees. head before heart.