The last two posts above mine are probably close to why you wake up tired every day: 1. Painkillers will repress your REM sleep and in effect you are dozing off and not getting the "right " kind of sleep, more like you are passing out rather than sleeping.
2. I had a lot of trouble with my breathing a few years ago. My wife said that I would stop breathing for a ling period of time and then start back up with a gasp. I got me some of the nasal strips (Breathe Right) and use them every night and it helps tremendously. Also , you may want to go to a dentist and ask him if you grind your teeth at night. This was another problem I had and I woke up tired every single day. Dentist gave me a mouthguard and now I sleep four hours a night, like a baby.
Remember its not how many hours you sleep, its the quality of the sleep you get. Like I said above, I sleep only four hours, like from 10pm to 2 am and get up for work. I feel energized and alert , never fatigued.
Hell, if you are battling yourself in your sleep, its no wonder you cant get started in the morning.You may be asleep , but you arent getting the sleep you need.
Peace
Lounatik