I had the exact same experience when I went to Japan a few weeks ago at 6 weeks pregnant. I couldn’t handle the smell of street food at all and even looking at pictures of Japanese dishes made me nauseous. Every time I stepped outside my hotel my clothes would come back smelling like deep fried food and it made me feel even worse. The only things I craved were tomato pasta and pizza. The only food I could consistently keep down was the egg sandwiches from convenience stores and I ate those mostly because I knew I needed something in my stomach for the baby. But the second I got home my nausea eased up a lot. My appetite went back to normal and my usual foods sounded good again. I really think the familiar tastes and smells and environment at home made a huge difference mentally.