Presentation in a few days..

Presentation in a few days.. So I have a 15 minute+ presentation to do in a few days and I am extremely nervous about it. My professor is huge on being able to speak publicly and to verbally convey ideas in a clear and coherent manner. With a stutter, I obviously can't be as clear and coherent as I want to be, so now I'm scared to do this. My stutters have always been blocks and I do it in my casual conversations with friends. But when I get up in front of my class, I freeze up and it gets amplified so much that I stop at every other word. Does anyone have any tips to mentally prepare myself for this day?