White hair horror, help!

I am in need of serious help here. In fact I am terrified as I am typing this. It started two years ago when I was 24. I now have various white hair increasing from random areas. The worst part of is, I have NO IDEA what's causing this. If it's solely from distress I can believe it but I just checked my cortisol levels and they came out normal. I don't even know if that even relates to my distress that makes me suffer though. Anyways, I have no family of history of white hair occurring at such age but I am just thinking if it could be from ironing my hair almost everyday or staying in the sun for about 10 -15 minutes... random things like that? I have no clue but I know I can't live with this. I keep plucking them out with tweezers. What in the world could cause it to happen at this age?? Tweet