What Causes Headache After Sex?

Hi, may I answer your health queries right now ? Please type your query here...I realized I'm not getting a orgasm during sex, and I try to focus really hard, but when I,m thru and I stand up I get these headaches feeling like my inside my head is strained, and yesterday morning I jus started getting this straining feeling and headaches and my eyes hurts also, I still have this feeling. Please guide me on what could be wrong. My whole head and neck hurts.