I can't offer more advice, but I did have a Mean Kitty once, years ago. She was so mean she hated her own kittens and would sit growling at them. There was nothing physically wrong with her, and she had milk, but refused to feed them. I managed to keep three of four alive with watered yogurt (before you could get kitten formula).

She never bothered with the other two cats (except that one time that caused the kittens, and she beat him up immediately after). She wasn't fond of people either. She had a bit of angora or persian in her, midlength hair, flattish face, all black and large round deep yellow eyes. Used to sit on top of the fridge and glare balefully at guests until they got visibly nervous, then she'd jump down and streak past them - always made 'em jump. She liked me, and that's all, but i got clawed by her a few times and no other cat of mine has ever been a scratcher.