Every time I go back home, after an official business trip, I always feel tired.

In fact,This is true even though during the trip I didon’t do physical labor work.

I just followed the planned schedule, visiting and learning.

MeanwhileHowever, I usually go to bed later and get up early during the trip, which tires me out.

You should either use both "later" and "earlier", or "late" and "early".

I didon’t mean to, it was just a natural state. It just happens.

"Natural" has positive connotations, but what you're describing had negative effects, so I changed it to "It just happens".

But when I rgeturned home, my thoughts relaxed at once.

I didon’t get up earlyier in the morning but woake up naturally at the regular time.

Maybe during the trip, although you didn’I don't need to do labor work, yourphysical labor, {my work forces me to concentrate|I experience stress|my thoughts are in an intense state for work reasons}.

So wWhen youI get home, youI don’t need to think about work anymore.

Maybe this is the reason why youI feel tired during an official business trip and youI feel relaxed when youI return [home].

You don't need to say both "return" and "home". You could say "return", or you could say "get home" or "come home".