If you're waking up feeling tired in the morning and you are sure you have had enough sleep then it may be what you are eating before you go to sleep. I find it better not to eat at least a couple of hours before going to sleep but in fact I usually don't eat for three hours before sleeping.
If you eat any simple carbs or High GL carbs at night then it seems to prime your system while you sleep. Do you have trouble going to sleep, it's almost a sure sign that this is causing the problem. The other possible reason, and I'm not so sure why this happens, is that you're eating too much high fat foods before sleeping. If I eat allot of cheese or fatty meat before sleeping, I wake up feeling zapped.. Really drained.
Keep your high GL carbs for the morning when you get up. For some reason you seem to need some high GL foods then as your glycogen stores are almost empty when you wake up.
It could be a lot of things. Your thyroid, your testosterone, quality of your night sleep, your diet, the stress, blood pressure,.... Try to look back in your life to see what has changed since this problem started.