What Causes Persistent Headache At Back Of Head?

Hello,I am a 26 year old female. Recently, I have been getting mild to moderate headaches around the same time each night. Tonight I have a moderate headache on the right side of my head. - About three days ago I banged the back of my head on the bottom of my fridge door. Should I be concerned? I am also experiencing ringing in my ears - but I ve had that as long as I can remember... what should I do?