What is this? Help, ladies!

So I’ve been fine with health all my life- more than that, I’d say, I eat healthy and work out daily and all that. Now suddenly my body has begun to react all at once. Ridiculously heavy periods alternate with skipping them, I’m suddenly anemic, my blood counts on basically Everything is off the charts, and I’ve developed a severe allergy to gluten, dairy, and several kinds of meats over the course of a few months. My heart and thyroid are also going haywire, apparently. I’m really scared... like I said, I was eating healthy and working out regularly and then this hit me out of nowhere! My bloodwork is so crazy the doctors don’t really know what to make of it... I’m just under 20 years old, my body should just be hitting its prime! Ugh... I’m really just so scared. Even if you don’t know what it is, a little encouragement would be nice :) I don’t really feel like I can turn to anybody right now.