How To Save Newborn Kittens?

Today, my roommates cat tried to eat one of her own. I managed to stop them just in time. The poor kitten was screaming -- it's a newborn. Now I am unsure what to do with the mom, and the babies. I have separated the mom, however, the kittens need to eat and I don't have formula or a tube. I'm not sure how long newborns can go without food since all the veterinarians are closed until tomorrow. I really want to save these cats. Also, the mother lost trust in me since I had to pick it up then it started attacking me so I had to throw them away from me and the kittens. I feel really depressed about this and I don't think I can tolerate seeing a dead newborn. Is there anyway of feeding them. I heard rice water is a good supplement for food replace for short term, however, I have potatoes. Can Potato water be a good supplement? I now need to figure out what I can use as a tube to feed the babies and how to feed them.