i have a cat that is around the age of 11-12. He has never had any problems in the past, very healthy. but he is pretty over weight but that’s really it. he hasn’t been peeing in his liter box, been peeing around the house, today he threw up and fell over and had a hard time standing up. he was breathing funny and when i was rubbing his belly he was purring very loud. i can’t take him to a vet because my parents don’t want to pay the money. what is going on?