Hi man, I have been there myself. Recently I have given 4 presentations in colleague and in all of them I stuttered. The only thing I can told you is to go and face the thing. It doesn’t matter if you stutter or not. In the end everyone does. We just stutter a little more. The important and only thing is to give the presentation and aprove. I can reassure you that they won’t fail because you stutter. In fact is an advantage lol. The key to this is to face the thing you are most terrified and do it. After you give the presentation you will be relax and proud of yourself. I have recently skipped some jobs interviews and I want to take that back. Running from things doesn’t make you feel better. You are the bravest dude!