appearence after years of meth use? please only answer if you have used meth.?

I have been using meth since I was 15 & I am now 29. I started using consistantly when I was 20 and have had only a few breaks, 3 months being the longest. I have always looked young but this past year I seem to have aged A LOT!

My hair is thinning and turning white, my skin is terrible. Overall my helath is bad and it shows. I know this is a result from my drug use. I am entering a rehab soon for the first time. I know once I’m healthy I will start looking better but my question is how much better? 15 yrs of drug abuse is a long time. Are there any meth users that have used for a long time and are now sober that can tell me how much of an improvement my appearence will be? Mostly in reference to my hair and face. Please be honest. Please only answer if you have used meth for a long time and are now sober. Thank you.