What Leads To Persistent Headache?

I have a headache for 5 weeks now. My head feels hot (only in the evening) as if I had a fever but I have no fever. I have a history of inflamation in my blood......? Past medical conditions never were diagnosed.....? Some doctors thought I had rumatic fever, but other were saying no. It seems that every 20 years or so I get very sich (without getting weak) but the medical people don t seems able to find what I have. I was sick like that in 1973 and again around 1993 and again now (2015) Could this be a virus or a bacteria who attack me every now and then and after making me sick for a few months returns to it s state of hybernation.....?