Same boat here. Was most addicted to benzos too and oxy. Man was my stutter wurse when I decided to get clean. Almost couldn't talk, anxiety to the roof. But now I'm clean for longer than 6 months, my stutter is far less and it does get better, so too you. What can help... Sing the sentences in your head when u speak. Maybe it'll come out a little singy but who the fuck cares. You own it bro!!