Normally nausea is very transient and subsides after a few hours. But you did take more than what is generally prescribed as a single dose so it may persist. If you can get some Zofran, that would be ideal to treat the nausea, but as it is generally by prescription only you may be stuck with otc remedies. I personally like Emetrol, but Pepto Bismal or a good ginger supplement could help. I also find that actully vomitting is the best cure, but not saying to force yourself. But dont hold it back if its coming up.