My husband and I had something similar last year to what you are describing, and doc visits did not produce any answers for us, either.

I personally believe it is A) unrelated to reptiles, and B) something that has not yet been medically identified.
Which is sort of creepy, but there you go. What makes you feel nauseous for an entire month, or longer? Not salmonella. Also, not stress, because there wasn't any more of that than usual.
I think something odd is going around, and it's a purely human illness.