I just adopted semi feral cat. I have owned cats all my life and this is new to me. 4 days in, he has been fully vetted and they wanted to barn him. He eats, uses litter box, and occ.lets me pet him through bars on crate. Is very frightened, hisses alot and swipes with his paws. I have a 20 yo domesticated cat who can get near crate without a problem. I do believe there is hope for this fur baby, but need some help with direction. Thank you!