Numerous shapes and sizes of litter pans are available, including those with high sides and a lip, or completely enclosed. Keep him outside so he can't bug ya. If he persists in bothering you, you might want to ask yourself if you've remembered to feed him. He used to play, but now he sleeps all the time. Well, get rid of that old one and get a kitten.
Cats get boring when they get old.
Cats spend at least 18 hours out of every 24 sleeping, and will sleep even more if they're bored. Spend some time daily with your cat, letting it chase a feather or string. I changed furniture, and her fur doesn't match my new colors. Maybe you can sell her to a pet store. You are entirely too much of a dolt to have a pet.