I have the same problem. Can literally sleep 3 days straight. My sleep doc says I need 12 hrs (and even then I have fatigue). I have periodic leg movements. I did not even know. I sleep at most one hour then wake up but go back to sleep & don't know. It csm be relayed to restless legs or neurological disorders. He thought I had delayed sleep phase disorder & restless legs but then I had a test. The medicine for it is making me tired. So, not sure what tp tell u but I hope the sleep neuro will help.