Cat nibbles fingers, it hurts?

Gee I don't know, perhaps we could try not hitting him for wanting to show affection therefore making him think that he's being bad? Don't swat him, no matter how light, just hiss and move him away, ANY sort of swatting or hitting will upset him and he'll do it more because he's trying to, in his mind, make things better, I swat mine but only if they're actually doing something wrong and they won't respond to hissing, if he's a problem at night then put him in a carrier or a crate but stop with the swatting, it's confusing him which is why he then bites harder. You could always also make sure to tire him out with play about an hour to half an hour before you go to bed so he'll just sleep when you do. But seriously, no more swatting. Hissing, a water bottle; Yes but no more swatting.