I think im grinding my teeth in my sleep, and its causing me to wake up to a aching molar every day. its only a single molar, and its not showing any signs i know of being rotten. could it be grinding my teeth? how long should the pain last?

You may well be grinding your teeth and you should have your dentist examine you. The masseters are the most power muscle in the human body ( the only pennant muscles in the skeletal system) they release endorphins on continual clenching and the brain gets hooked on that. You may need a "bite guard" that can relieve undue pressure on a single tooth and stop the pain, but do get checked.

You may be under a lot anxiety and stress causing you to grind your teeth at night. A night guard that you wear at night should be constructed by your dentist so that you grind on it and not your teeth. It is a soft or hard appliance that will absorb the pressure on your teeth. Eliminate your anxiety and stress and no more grinding at night.