My Husband Has These Episodes Where He Gets So Tired

My husband has these episodes where he gets so tired he just has to lay down and put his cpap on and sleep for a couple of hours. THen he is better. But the symptoms are - these episodes come on quickly, he can hardly even walk from where he is to get to his bed. I and my sister also have these episodes to a lesser degree, where we HAVE to go sit down when we are doing even the smallest of projects, like doing dishes, vacuuming, taking a shower can be hard for us at times and completely wears us out. My husband also gets this. Then he goes into the episode I described in the beginning of this message.