Premature Greying of Hair at age of 17.

I saw 2,3 white hairs at the age of 17 and then it increased to like 10,12 now when I am 18. Some of them are always exposed and everyone can notice them somtimes. Sometimes they are hidden. It's not too much but my family can point them too often nowadays. Though my hair is completely black and only a few are white,but in every part of my head,front,left,right or back,there has to be atleast 1 white hair. Even my friends spot it now,though they are not too much to be seen but the ones that are white keep popping up now and then. My medical history is already very bad at this age:I have high blood pressure from the age of 15 and now I am taking BP meds: Concor COR 2.5 and Myotan CN 40/10. I also have high sugar but not diabetes,it's 100 in fasting. Also my cholesterol levels were high-normal,but doctors said they are ok.I also have L5-S1 disc herniation and degenerative disc disease in my spine.I took root block injection and many medicines. Also have stomach/intestine problems. Help.