Smoke Marijuana, Cigarettes Daily. Hair Very Thin. Will It Grow Back On Stopping Smoking?

Hi, I ve been smoking marijuana on a daily basis for about a decade now. Also smoke cigarettes. My once full head of hair is now extremely thin. I ve stopped smoking both cigs and marijuana for a week or 2 at a time and noticed a lot of little hairs growing back but starting smoking before I could see the hairs grow long. After I started smoking again the little hairs I noticed growing back fell out again. My question is, do you think my hair will grow back fully if I stop smoking all together? Thank you