Take yourself a slow, deep breath, using your thoracic diaphragm, exhale slowly through pursed lips. Chillax... While it's not good to have your body attacking itself, as happens with autoimmune stuff, you also shouldn't fret yourself so. It can take quite a while to get a diagnosis. So many disease "look like", or mimic, other diseases, so doctors are usually quite careful with diagnoses. Has your thyroid been checked?