My Lab gave birth three weeks ago to 10 puppies. She hasn't been feeding often and she is losing fur and seems depressed. What could be wrong with her? What more can I do to helper and the pups?

My Lab gave birth three weeks ago. It is her first litter, and it was unplanned. She had 10 puppies. She didn't have very much milk to begin with and it doesn't seem like she has much more than she did. She hasn't been feeding very often nor does she stay in the whelping box very long. She is starting to act depressed she is loosing her fur, and is still discharging. We had her to the vet when she had the pups and we have her on a calcium vitamin and we feed them goats milk to try to take some of the feeding pressures off her bruised breasts,and to get her to develop more milk in between her feedings What could be wrong with her? What more can I do to help her and the pups?