Hello, I am 29 years old, 215lbs and 5 6. Last week I had what I thought was a toothache on the left upper side of my mouth but my dentist found nothing. A day later I started having left sided headaches and fatigue. Friday afternoon I had my first ever bloody nose but only from the left nostril. Today I woke up with a lump behind my left ear that is painful to touch, very hard and doesn t move. Could this be an infection? Or something more serious?