Struggling with Undiagnosed Autoimmune Disorder

I have been having issues that line up with an autoimmune disorder for months. I have had multiple specialists tell me to get tested for autoimmune disorders. My doctor just did blood work last week for a few that we think I might have. He did warn me that because I’ve only had symptoms for a couple months and because I am only 17, that even if I do have one of them that we tested for it might not show up. Just got all my test results back and everything is “normal”. So now we get to do further testing, if that’s all normal then we just play the waiting game and hope that when we test next time I get some answers. Even though I knew this was a possibility, I am devastated. You’d think that everything coming up normal would be good but, this just means I have to deal with even more testing, more draining doctors appointments, more pain, and feeling like shit 24/7, more people not taking me seriously because it’s undiagnosed, etc etc. I know getting diagnosed is a long process, but I was hoping that maybe something would finally go my way and that a diagnosis would give me some form of closure or reassurance. So now we’re back to square one. Now I’m stuck wondering how many more times I have to miss school, work, important events, and more, just because I am so mentally and physically drained from whatever is going on. Did/Does anyone else have this issue? How did you cope with it? Did you also have moments where you thought you were just overreacting and maybe nothing was actually wrong?