Help my Chonky Boy Bubba

This is Bubba. Bubba is my ~10 y/o chunky boy. He is 27 pounds of pure love. He lives at home (Missouri) with my mom. We have been unable to get Bubba to a vet due to financial difficulties. As of the past few months, Bubba has been using the bathroom on the floor in front of his litter box, which makes us think he may have a urinary problem which we need to get looked at.

We’ve tried everything from multiple litter boxes, moving the litter box, changing the type of litter, food he eats, etc., but to no avail. I appreciate any and all help as I want nothing more for my chunker to be healthy and happy and live as long as possible