Premature Greying of Hairs, Please Help.

When I was 17,from then I am finding few completely white hair strands on my head. It has only grown since then,though they are only like 14-15 all over the head that I found. I have fatty liver disorder and also GERD and usually have stomach and intestinal issues. I took a lot of stress as well and got high blood pressure,currently on medication for it. Please doctors help me. They always pop up in the front and are always visible. This is taking away my confidence. I feel like they will keep growing in numbers as I age. Can it be stopped or reversed? If the cause is treated,then will my premature greying of hair not worsen further? Please suggest something. Give me some advices and answers to my questions. I really need help and assurance. Thank You Doctors.