Suggest Treatment For Intermittent Headache

Hi, may I answehello doctor!
i'm a 17 year old girl... from past 4 years i'm getting severe headaches on and off...in the back part of my head.... consulted so many doctors but they all say different things...right now i'm studyin n i'm soo scared about it and seems like i'm having concentration problems..i can't co-op up with my studies! 4 years back while playin with my brother...he pushed me back and my head hit hard on the wall...other than that i dint have any injuries for my head.r your health queries right now ? Please typ