Dent In Head, Bad Headaches, Sleeplessness, Lack Of Concentration. What Can Help?

Hello. My name is Makia. I am fifteen years old. I've had a dent in the top, middle section of my head for a while. I can't remember when I first noticed it, but I do remember it started bothering me when I was in the 7th grade (I'm in the 10th now). It's very tender to the touch. If I take 3 fingers and rub the spot I feel something like a little bone or something rubbing against my skin. I get bad headaches and sometimes migraines when I'm in hot weather. Sometimes any little noise can make me have a headache. I don't know if this is related to the dent in my head but sometimes it's hard for me to wake up from sleep, and sometimes it's hard for me to fall asleep. I have also been getting frustrated alot more, and its hard for me to concentrate. Please tell me what could be wrong?? I'm going to the emergency room tomorrow. Most neurologists in my area won't see teens until their at least 16 years old.