Same situation here. I would suggest to reach out to an organization for support. I don't know what country you are in but there are many organizations such as Stamily.org, or CampSay.org or the National Stuttering Association in the United States. What helped me was practice my diaphragmatic breathing, reading a book out loud on a daily basis and practicing in front if a mirror. For me, this raised my confidence level and I still have blocks but I don't dwell on it. I breathe and move on. Also, those who mock you have their own demons to sort out. Just know that YOU ARE AWESOME!!!! Also, google "Stuttering" and you'll find videos from all around the world from people who stutter and how they deal with life's stressors. Take care and be well.