I feel a dent/bump on left side of head just above scalp line. Should i be worried?

[M1llerTim3360]

I am 22 years old and recently I felt what feels like a line/dent or something on the top left side of my head just above the scalp line. I am very worried about it because it just doesn't feel right to me. Can it be an enlarged artery or vein or something? Sometimes I get headaches at night but I'm If that's from looking at a screen for long periods of time. Sometimes when I move my head quickly or suddenly stand up, I slightly become a bit dizzy but nothing serious. Sometimes when I'm sitting down and suddenly stand up at work, I get a sudden head rush and become light headed but then when I lean over, everyrhing suddenly goes back to normal. The last time I recall hitting my head extremely hard was months ago probably in September. I felt fine afterwards though and didn't notice anything out of the ordinary. I'm just wondering if this line/bump on the top of my scalp line is serious. It doesn't hurt to the touch. I was also recently diagnosed with a deviated septum along with polyps and nose blockage and I also have had an enlarged lymph node on the side of my neck for a while now. Can these have anything to do with it? I am stressed out about this. Its been months I feel but I'm still a bit worried.