I Am Experiencing Tenderness At The Base Of My Skull

I am experiencing tenderness at the base of my skull on either sides of my spine, not on my spine though. Pain started 3 days ago and feels a bit enflamed. It has a dull pain and is tender to the touch.
Also, I have a mystery lump on the top of my head, appeared the same time as the tenderness on the base of my head began. Diameter of the lump is approximately the size of a nickel. Also tender to the touch. Thoughts?