I kind of had the same feeling. A lot of my classes, my professor had us stand up and introduce ourselves to the class (name, major, current job, etc). This was the worst for me, especially if I was one of the last to go. College isn't like high school where a teacher would randomly call on somebody for an answer. You WILL have to do presentations in certain classes. It's something I just owned up to. I stutter, oh well. A tip I can give for presenting is to approach it with confidence. Half the class isn't really paying attention when you'd be presenting. And if you appear to be confident, you'd be the only one to notice that you're stuttering. It's 6am and I haven't had much sleep so I'm kind of rambling, but you'll be fine. I'd avoid speaking to the professor because they'll notice it eventually.