Hi My Name Is Amber. I Have A Dark Line

Hi my name is Amber. I have a dark line in the middle of my head. I have not always had it. When i was younger around 17 the corner of a small computer feel on my head leaving a small scar. At this time i did not have the line that i knew of. At age 24 i hit my head really bad on the corner of a chair in almost the same spot. I really think it caused a concussion was very painful for a few days and i had a lump that was there for a while. Maybe a month or so after i noticed the line. That was maybe a 7 months ago i still have the line. What could be the problem with this? I feelvery self conscious about it. Is there anything at home i can do to lighten it up? When i touch i kind of feel an indent along the line but im not sure if it always been there. Help me please if you can.