Hair Loss.

so this is WAY beyond my comfort zone, but I'm in dire need of help. I have lost 90% of my hair over the course of the last three months. I've been to the doctor, dermo, and many other places. I've got blood drawn, ultrasounds, nothing physically came up. I have a special shampoo and conditioner and take Bioton everyday. Everyone says that it's from stress, and I know that stress WILL do this to you. Being a freshman in highschool many people don't grasp just how overwhelming this is. Anyone with advice, opinions on what to do, or anything of the sort please feel free to be honest.