mbacas is right about the cpap machine...my sleep study found that I (unbeknownst to me) woke up approximately six times an hour because of not breathing and at one point stopped breathing for a minute and a half! No wonder I was so tired! I'd sleep for eight hours but woke up feeling like I went five rounds with Oscar Delahoya.
I would highly recommend a sleep study.
The cpap does take some getting used to. On mine it's a mask that covers your nose and is held on with straps that go around your head. You can't really talk with it on because of the air being forced into it so you look like Hannibal Lechter and sound like Darth Vader if you try to talk. However, the benefits far outweigh the other.