I used to have a bad stutter and I still stutter now, it’s just not nearly as bad. What I did was a. Get speech therapy which kinda helped but not really and b. Put myself into situations that would be nerve racking for any person who stutters. I volunteered to give presentations, raised my hand in school, staffed as a camp counselor, and I worked jobs that required speaking. For some reason this really helped me get over that fear and just get used to speaking, so I know and have practice making myself speak better in situations. I don’t think this strategy would help for every person because each person is unique and different in their stutter and how they cope, but it worked for me.