My biggest problem in my life

My biggest problem in my life I am 21 years old, I stutter in speaking since I was in school. Now I am in college and my biggest fear is making a presentation in lectures or speaking out loud in the lecture if the instructor asked me to answer or read something. Guys this problem I can't get over it and if I got over it, I am sure my life will take a different path and will be changed 180 degrees. I am getting closer to my Grad project and this will be the longest presentation I will ever make, I am afraid of it from now. The problem is I think allt about the people infront of me when I stutter , I always think they will make fun of me. Guys I need any help or practice I can make, this is literally my biggest problem in my life.