Sleep apnea is a likely possibility in this case, but we probably shouldn't try to diagnose remotely. That being said, if you feel like you're sleeping and it's just not working - you wake up tired, you have trouble waking up - then it's certainly worth checking out. Sleep apnea is often associated with particularly enthusiastic snoring, so if people remark on your snoring, this might be indicative. Sleep apnea is also associated with being overweight - it's largely a mechanical obstruction of the airway in sleep, as I understand, which is aggravated by obesity.
If you're skinny as a rail and sleep silently, it may be that you have a different sleep issue - or not.
I want to echo the advice that others have given: sleep apnea is serious juju. If you think it's an issue, find out for sure, because it's not likely to go away on its own and it'll really mess you up.