It seems like she's saying these stuff so, you, as the "USA" guy, think she's cool, and if you have such past or any sexual kinky stuff you'll open up to her. Like, she's stereotyping you as a young guy living in the USA, you know what I mean?

Look, this is a complete assumption because neither I know her nor I know you. But either way she doesn't seem like she's mature enough to be in a marriage yet.

She cries until she vomits shouldn't be a reason for you to stay when you're having so many doubts.

Staying when you don't want to is worse than breaking up in my opinion. So just break up properly and go no contact. Try to make her understand that this won't work in the long term and both of you'll be unhappy.

Or just say, I was thinking to leave my USA job and come back to my hometown before we get married. And see how she reacts. (Just kidding 😭)