Your world is fine until the phone rings. You get that call and the world shrinks and priorities change and you enter a world you did not know.
The best definition of culture shock I've heard is that it's like moving into a new home and in each room you have to remember where the light switch is. You have to spend your time thinking about things you normally do without thinking. That's why it's exhausting. You don't normally think about where the dishes go or when the garbage is picked up. You just know.
In your new medical culture you have to think about everything. In the hospital it's how to park, when and where to eat, how to call the patient's room, who to contact back home with news. At home it's medical schedules and doctor visits, and home health. There's the new language you're learning and the new set of finances to deal with, and new people's names to remember. It's exhausting.
So do what expats do. Start by acknowledging what you're leaving behind. Choose what you will now make time for and shelve the rest. Step into your new culture expecting only that your expectations will not be met. Go in as a listener. Take notes. Let the medical professionals and other people in your new culture tell you how it is here. And if you don't understand something, ask. Better to feel foolish than to be lost.
Get on your feet. Your patient needs you. It's a new world.