Food intolerance after moving here?

I moved here in September, and since then I’ve been having frequent on and off stomach issues (I’m going to finally go to a doctor soon), I’ve been wondering if it’s a difference in Japanese food.
At first I assumed I just needed to get used to it and it would stop since I just moved across the world, but it hasn’t. On top of that I’m having a hard time figuring out what could be causing the issues. Food seems like the obvious cause since my diet has changed since I arrived but I’ve also been trying to cut out things I thought could be the cause, but I’m still at a loss. My next test is cutting out raw fish since I didn’t eat any of that before coming out here and I’ve heard some people have a reaction to it.

Whether it’s developing a food intolerance randomly or just not agreeing with Japanese food, I was wondering if anyone else had a similar experience, where they were fine in their home country?

by Cherry_Shortbread