A Strange Problem Feeling A Burning Sensation In The Back Of My Head

Hello. I am 23 years old and honestly I don t know what is wrong with me, but I hope that you can tell me. In the end of March this year I started feeling a burning sensation in the back of my head (in the right part). When I touched it I felt something like a swelling (half a cm) - as if I ve bumped my head against something and a lump has appeared in that spot. But I haven t bumped my head anywhere. Eventually that burning sensation continued approximately one week. After that everything calmed down, I had no problems in the summer. But now, quite recently, I started having a burning sensation again and my neck started stiffing. Anyway, the lump in the back of my head (in the right part) is still there. The neck goes stiff from time to time. Basically that s all. I haven t felt any pain there, just an annoying burning sensation and a lump.