suggest dermatologist for acne and premature greying?

I'm 17, I've had acne, cystic acne, hyperpigmentation and comedones since months and am tired of using all sorts of products since. I've went to a dermatologist for my hairs issue but haven't seen any progress since. The greying issue has been with me since I was 14. So looking for a dermatologist who would clear this up.