You could just make your own whey. It's easy to do. If you have a source for raw milk, just put the milk in a jar and let it sit out on the cabinet for a couple of days. The whey will separate from the curds (curds and whey!!). Pour the whey through some cheesecloth or a clean dish towel that isn't too thick and let it hang to finish draining for an hour or so. You can take the curds and add some salt and pepper, or garlic salt, or whatever seasoning you like. You might be able to tolerate it since it will still have all the enzymes intact. You can drink the whey. Sally Fallon's "Nourishing Traditions" book talks alot about all this.
Also, another good source of protein and nutrition is bone broth. You can use chicken or beef. Put a roast of some kind that has bones, or a chicken, in the crockpot or in a pot on the stove and let it cook for a few hours. Then drink the broth. You can then add some veggies to the broth if you want to give it some more flavor and cook it some more, with the bones in it. If you use a chicken, make sure you strain all the small bones out. Drink the broth, and if you feel up to it, eat some of the veggies that will be very mushy after cooking for awhile. I use potato, carrot, garlic, onion. Again, this info is in Sally Fallon's book.