Im a 35 year old woman with history of fibromyalgia for the past 18 months. I also have tmj and bruxism for which i wear a hard night guard. I do suffer with headaches but for the past few weeks i have been experiencing a throbbing tightening type pain in my head when i stand up or sit down or roll over too quick on bed. Today i also started feeling very clammy and weak. What could be wrong? My pulse rate is70bpm and temp is normal.