Does anyone know of anyone who has reversed their grey hairs??

I am a 36 year old female and am noticing loads of grey hairs. It is not hereditary in my family at all. My sister is 3 years older and has only seen a few on her head and my grandmother (Indian) had a full head of dark hair until she was well into her sixties! (She did used to treat her hair with some natural stuff regularly though (not a colour) ). I have had a lot of stress over the last few years and must be having some hormonal problems as well because I'm having other sorts of problems. I would like to know if I try to reduce the stress and try other things whether my hair will go back to normal or whether I am stuck with it now.