What Causes Tiredness And Body Pain?

I have been very tired the last 4 days, for the last two days I have had an increase in my pain in my neck, shoulders, and wrists. I have also had sensitivity to all my teeth. I have been taking my muscle relaxers, and anti- inflamatories, resting, and doing my stretches and physical therapy. My husband theorized that maybe I have some kind of sinus infection that is causing all the jaw and muscle aches