Hello: have u ever discussed this issue with any student services department at your college? Have you ever spoken to this professor directly before? Are they aware of your struggles? How big is the class? Do your classmates know you stutter? When is the exam? Just a handful of questions to help put some parameters around what you are facing. I'm a college prof - who used to stutter horribly when younger (so i know how internally-knotted you are about this!), but by the time i got to college it was less noticeable.