I have been craving protein ever other day. And only protein like eggs steak chicken animal by-products not peanuts. Why?!

Your body's wisdom. I believe that the body has an innate sense of what will work best for it and what it needs. If you and your body are "craving" eggs, steak, and chicken (and not peanuts), I might consider "going with the flow" and giving your body what it wants (and avoiding what it doesn't). Now if your body is craving alcohol, cigarettes, sweets, etc., perhaps I would be more hesitant to go with the flow...
Craving. Your craving could well be normal, depending on your age & health status. If worried, ask your pcp to run blood work to check liver & kidney functions.