Re: epstein barr responsible??
Don't quit looking for answers but get some hormone blood work done. Cortisol, PTH, and DHEA, if these are off see an endocronologist.
This is just a suggestion and may lead nowhere but there seems to be a connection between CFS & Fibromyalgia and endocrine hormones. Also large doses of steroids can lead to pituatary damage so if you have been treated for chronic pain with steroids the risk that the pituatary is damaged is a very real issue.
Endrocine diseases are often misdiagnosed as CFS (chronic fatigue syndrome) and Fibromyalgia, depression, panic attacks, etc.
people with endocrine disorders often get sick easy because the endocrine disorder can depress the immune system.