For each month you are away, expect at least a week to readjust to pace of life. Expect to be unexpectedly tired long after jet lag should wear off. It is not jet lag. It is pace of life lag.
Avoid big box stores for a week or two. Don’t be tempted by the visions of cheap paper towels and laundry soap. The sheer acreage of goods might be somewhat daunting.
Same with the health club, library, and highways.
No one is going to really understand your experiences in your host country. Keep writing in your blog.
The flurry of emails from friends in your host country will die down, but don’t let them. Email someone once a week.
Expect people to tell you about their experiences in your host country. Expect to make unexpected connections with such people.
Having a few items from your host country in your office makes it less lonely.
You have changed. Life has gone on the same at home. It is normal be “homesick.”
Learn to make some of the cuisine you enjoyed in your host country.
Eventually, American coffee will seem strong enough.
Plan for your next adventure, achievement, and then take a nap. Because you will be tired for a while, especially if you have to go right back to the flow of things.