About Five Years Ago I Got Into A Forewheeler Accident.

About five years ago I got into a forewheeler accident. I never went to the doctors like I should oF. Since then, I've had a dent in my skull. At certain times I will have very bad headaches or have headaches for days. I don't know if I should go in and have it checked out. I honestly don't even know what kind of doctor I need to go too. Please help..