If you have no goats milk you can feed 3 quarts of whole cows milk mixed with one quart of cream. It will take a while for baby to get used to it. I like to use Pritchard nipples.
Mastitis? Yeah baby shouldn't drink that milk but you need to keep trying to strip the bad milk out of both sides of the udder. And there is a good cow medication you actually put in the teat to clear up the infection.
Co-op used to have it when i lived in TN. There are 2 types, one is called Today and one is called Tomorrow i think. You need to get the one for a doe in milk. Its been years since i had goats so i forget which it is.