What Causes Headache Radiating Across Bottom/back Of Head?

I have a horrible headache that right now radiates across the top of my head from ear to ear. Earlier it was radiating across the bottom/back of my head. I also feel a lot of pain behind in my sinuses, like a bad sinus infection. However, I have clear mucus when I blow my nose. My body aches all over. My head also feels like I have a split open basketball over it and there is a lot of loud noise in my head.