What's the deal?

So a few posts ago I talked about how my energy was coming back. I was so excited! Unfortunately it wasn't back for long. I had quite a bit of energy for about a week, then it went down again. So I'm back to my "I need more sleep" thing. For example: on Saturday I woke up feeling great. I went outside and mowed the lawn, which wasn't hard work at all because we have a self-propelled mower, it just took an hour. When I was done mowing I was starting to feel tired. I showered, and then, even though I had been awake less than 2 hours, I took a nap. When I woke up I felt better again, but only for another hour, then I was tired again.
Sunday a similar thing happened. By the time church was over I was exhausted and wanted a nap really bad, but I couldn't take one until about 3:00. When I woke up after 6:00 I felt a lot better though...
Hopefully this is just a short relapse and I'll get energy back again soon....I think I'll go take a nap.