Women with hairloss….any advice?

HI,
i'm a healthy 24 year old suffering from hairloss.
Background info:
Not on the pill
Don't smoke
Drink occasionally

It started about 3 years ago. Doctors have done all kinds of test EVERYTHING came back normal.
I'm at my wits end. I would love if anyone could give me any advice which worked for them.

Thanks!
Its a diffuse thinning. I used to have lovely thick hair, now I can't wear me hair out. I have to tie it back. I have black hair, so against my white scalp you can really see where its thin. Im so depressed with it.