I understand your feelings, Brother It happened with me too.😀 There are few things that you have to keep in mind when you will give presentations. 1) Dont think about what everyone says about you. 2) While giving presentation, keep your mind relax , Stay calm and take a deep breath. 3) accept that you will stutter while presenting. When you accept this fact, bro 60% of your stutter will gone away. 4) dont feel ashamed of yourself, it is just a bad habit, nothing else. Bro, there is nothing that is impossible. Always keep in mind that it is only a bad habit of speech, it can be recovered. Do practice in front of mirror, talks to your friends and be happy 😇