My mother cat has 5 kittens that are 3 weeks old and for the past 2 days she screams every time they try to nurse I have been feeding them with a baby bottle, today I noticed her nipples are very swollen what do I do?

I not sure what to do about the nipples... I will see if I can find out some info and post it. Maybe someone will come along with good advice. You can start feeding the kittens some kitten food, if you use the dry type just moisten it with water and get it soft. If your using a milk replacement you could wet it with some of that.

I'd be concerned that the mother cat has an infection of the milk glands going on. Seems like a vet visit is in order here.