Throbbing pain in back of head

Woke up one weekend after drink the night before tried to drink some coffee and felt very ill to my stomach. Was trying to throw up but since I had nothing in my stomach all the pressure went to my head felt something snap or something of that nature and then my head started throbbing with pain. Here i go one week later and still have the throbbing head pain. It hurts at times when I move my head and at times it throbs without even moving it. The pain comes and goes all day long, my question is what could have caused this pain and why won't it go away? And by the way I also don't have any insurance to go to the doctors. Thanks, Cookie426