Poundcake1

I'm starting to think I have an allergy to whey Protein Isolate. I'm 4 weeks post op and find it harder and harder to tolerate. I'm weak and might be dehydrated too because I get the shakes, flushed, hot and cold and nauseated when I drink the Protein shake. Do you think it makes you more dehydrated? Did anyone ever have the same complication? I have no idea what I'm to do- Is there any alternate. I think soy is not so good for you either. Does anyone have any ideas.