Last Night I Developed A Bump 1 Inch Behind My

Last night I developed a bump 1 inch behind my ear, not larger than a nickel. By a few hours later the side/back of my head hurt. Not a headache. It feels like pressure on the skull under my skin. Today the bump is much smaller, but my head still hurts. Uncomfortable to the touch in a few places, like I banged it and it's swollen.