I understand where you are coming from, and I agree with Joy that it's hard to believe in something when so many don't. But then I tell myself that SOMETHING is wrong with me. "Normal" people don't hurt when someone touches them, they don't tire as easily, they don't have so much pain in the absence of any injury or easier to identify disease (like arthritis). So I guess whether or not we call it fibromyalgia (which unfortunately still carries a stigma to some), we have something.
I think it will be easier to accept when it becomes as accepted as other invisible illnesses. I feel certain that someday soon, the cause will be identified or at least a definitive test will be developed. But until then, I know that other similar illnesses have been ruled out, and I fit the current criteria for fibromyalgia, as established by the American College of Rheumatology. I've also been diagnosed by three different rheumatologists. So, until proven otherwise, I'm going to go with the fact that I have fibro and carry on with my life as such.
I honestly don't believe that the most highly regarded entities in American medicine, such as the American College of Rheumatology, the National Institutes of Health, the Mayo Clinic, etc. would name and discuss diagnosis and treatment of a disease that didn't exist. Some of the greatest minds in medicine have established fibromyalgia as a real illness with a diagnostic criteria, and I'm going to try to accept it.
I really like this summary discussing diagnosis from the Mayo Clinic:
www.mayoclinic.org/diseases-conditions/fibromyalgia/in-depth/fibromyalgia-symptoms/ART-20045401?p=1