I know it's sad to be told off for liking a cat, but I've seen people really concerned when other people start feeding their cats. Two of mine are on prescribed diets for medical conditions, but will still polish off anything put in front of them. Cuddling them and chatting is fine, but tbh being an alternative diner for them is not really a good idea.
You'd be fine getting your own cat, jeza - they don't need the vets that often, and you could do what I do, just hop in a taxi on those infrequent occasions. They give you so much friendship, unconditionally, and they are wise little things, they just sense when you need a cuddle, too :-)