Recently my cat has been ripping out his fur a LOT more than normal. He's not grooming, but tearing it right out, and it's now around the hind or inside of his legs. He is around 9 years old, a black cat, neutered, less than obese, and have been giving him (probably) healthier food such as the Wellness Brand seafood dry food and Natural seafood wet food, sometimes giving him Friskies wet food as a reward. Before, his diet was all Whiskas brand, the dry and wet food that were chicken flavoured and the treats that were dairy or chicken too . He has sensitive skin- I can touch his skin very lightly and he'll reflexively try to groom himself. He has no flea problems. He has had a problem of ripping his fur out before, but it was never serious, just a tuff or two once a month. Now he's been pulling out handfuls of fur a day and there are very visible patches of bald spots. My sister has tried putting on baby clothes to keep him from reaching the spots he was pulling the fur out for a few weeks. He manages to get his way out of them and continues ripping out his fur. My sister is pregnant and I think he's been reacting ever since. I feel he is falling into a state of depression. He's not very active lately and all he has been doing is pulling out his fur or sleeping. He doesn't like any people other than me, but he doesn't mind letting others touch him unless they tease him too much. He was quite itchy under his chin but mostly when I scratch him there, which I felt bumps and scabs. It has gotten better but the fur ripping is worse.
Is it allergies? Is it depression? Should I change his food? Is there a connection to cats and babies? My cat has never been fond of little kids or kittens. I can't afford to take him to the vet if the veterinarian tells me to buy medication for him. What should I do?