I use to oversleep too. Sometimes 16 hours a day. My doctor prescribed Adderall for me which does keep me awake. Some people recommend Provigil, but I hear alot of insurance companies will not cover it. Another thing that works is exercise. I know it's hard because you feel so tired, but once you start exercising, you will find that you have more energy and sleep less. I have also learned to get out of bed at the EXACT moment I wake up naturally. I use to just roll over and go back to sleep, but now I force myself out of bed. I also try going to sleep the same time every night and getting up the same time every morning even on weekends. And even with doing all of these things, there are still some days where I sleep too much. I've just come to accept it, and I try not to beat myself up to bad about it. I just hope that tomorrow will be a better day and that my sleep patterns will get back to normal.