Hello, I understand your problem. I would.like to say that this problem is quiet common on these days. And moreover it is more of familial type. If the your elders has got grey hair in their early lives then it would be the same with you. So I suggest you not to worry about it much and get going with it. You cannot turn back what has happened but if you want to prevent more of it then you need to consult a dermatologist for your assistance. Thank you