sounds like cfs , or me . im no expert tho ! they are both unrecognised medically in my country but in usa is more well known , there is a forum for fibromyalgia and cfs folk go there .copy and paste this there see what they come up with ! x x
Could be lyme disease. Fibromylgia and chronic fatigue (myalgic encephalomyelitis) are "syndromes" meaning a group of symptoms with no known cause. Many people get these secondary to a viral or bacterial infection like lyme disease, epstein barr virus and others. These are just things you can look into. I do not think it's in your head.