Well I Have Been Having This Problem On And Off

Well I have been having this problem on and off for a minute now but I always thought of it as a headache. Starting yesterday I had a sharp pain come only on the left side of my head and it would do it every couple of minutes. The only time it completely stops if I'm sleep or on its own. I've even taken over the counter meds to see if that would stop it but no help. Its now at a point where its starting to scare me. Do you have any suggestions of what you think this could be ?