Exhaustion is killing me! Dreading going back to work.

I’m a teacher for kids with significant emotional and cognitive disabilities so I have had the last week off and I am dreading going back to work tomorrow. My exhaustion has been insane this past week. Sleeping at least 10hours a night, sometimes 12, and still taking a 2-4 hour nap during the day. I have no idea how I am going to function tomorrow. When my kids are at a special class for an hour I seriously am thinking I will take a nap behind my desk. I don’t know how else I will survive! My kids are so demanding with there behaviors and I can’t afford to be off or the entire classroom turns into a behavioral nightmare. How do people survive this first trimester exhaustion???? I’m only 7 weeks 2days and the second trimester seems lightyears away.