What Causes Knots On Back Of Head Along With Light Headedness And Dizziness?

yes i have been having headaches for the past week ongoing. i have been dizzy and light headed. i cant even sleep at night cause they last all night, i have taken over the counter meds but nothings working. but i also have these three knots on the back of my head. one is located right behind my left ear and its the size of a golf ball and i have a small one located in the same spot on my right side. then i have a knot that recently came in the middle of my head, should i be worried???