Many people who have one autoimmune disease have more than one. Awesome news, right? I have a form of lupus; I also test positive for sjogrens, but to date that doesn't express itself, thankfully....
For what it's worth, don't give up. I had a chronic headache following a mini-stroke at age 38 - I'd had migraines for 15 or so years, this was different, an incredible, sharp pain that just NEVER...