In the United States, it's fine. It's one of at least four different pronunciations that are common and recognized by US dictionaries.
I learned and say "nawsha." Two different US dictionaries, Merriam-Webster and American Heritage, agree in listing all four pronunciations, with the second syllable beginning with "s," "sh," "z", or "zh." Unfortunately they their online websites don't use IPA.
https://www.merriam-webster.com/dictionary/nausea
nȯ-zē-ə , -sē-ə ; ˈnȯ-zhə , -shə
It has audio files.
As you see, the way I say it is the least common of the four.
A common usage argument involves the word "nauseous." In the US, it is common to say something "makes me nauseous," i.e. makes me feel nausea. Sticklers sometimes say this is incorrect usage. They say that a thing that causes nausea is "nauseous," the person who feels nausea is "nauseated."
As a kid, I found even the word "nausea" made me nauseous--I mean nauseated. The first time I read a children's version of Homer's epic poem about Ulysses, I was really bothered by the name "Nausicaa" and really wished Homer had called her by some other name.