unrestful sleep

Last night I got a terrible night's sleep. It seems that a few times a month I will toss and turn, doze in and out of sleep, and dream about not being able to sleep. When the alarm finally does go off, I am still exhausted. I know that I have gotten some sleep when this happens although I am not sure how much total. I do not know what triggers these bad nights. I have noticed they do tend to happen on Sundays most often. When it happens my mind does seem to be racing before hand and I can not seem to make it stop. I do try and watch a little TV before bed just to clear my head and slow down before bed. Maybe being up later the night before hurts me when trying to go to sleep although I am usually not up ridiculously late any night. Maybe if I take a nap that day, it comes back and hurts me. I don't know what causes it for sure. Any suggestions to solve my restless sleep problem?