Have Patchy Facial Hair. Reason?

Good day, I am 22 and can t grow proper facial hair , it s not really patchy it s more like 1 out of every 20 hairs on my chin is long and black the rest are white, same with my mustache . Then I have a random hair here and there where I am suppose to have sideburns. I also don t have any hair on the sides of my mouth only under my lip, chin and above my lips . I use to be an alcoholic in high school and don t go outside much. Any advice would be appreciated as to why most of my hairs don t grow the same length as these black ones that grow pretty fast. I can decide not to shave for a year and the blond hairs will not grow an inch yet the black ones will grow non stop why is this?