Lump On The Bottom Right Of Head, Pops And Goes Back, Painful Causing Headache, Dull Pain Into Ears. What Could It Be?

I have this lump on the bottom right back part of my head, i noticed it several years ago. It pops up then goes back down. But it is hard, it doesnt move, and it hurts pretty bad also causing somewhat of a headache . Also when i was younger i used to go roller skating alot, i fell multiple times skating backwards and hit my head in the same spot every single time and never got that looked at, but you can still feel that little bump almost like a calcium deposit. So i didnt know if this lump that keep recurring over and over again could be stemming from that or what. i just know it hurts and its also sending dull pain into my ear. or so it feels like.