After an exciting first week in the united states, bryan, an international student from malaysia, begins to feel exhausted, anxious, and confused about life in the united states. this is

The answer to this question is Culture shock
Culture shock refers to differentiation that happen to someone after experiencing a new culture that completely different from that person's.
when we grow up wiithin a certain culture, we tend to believe that it's the only way of living, so being exposed to a brand new culture that had certain differences with ours tend to cause psychological distress.