I have a stutter, and I recently graduate Magna Cum Laude from the UW Business school. I gave multiple presentations, including many hour and two-hour presentations, and I found that I felt much less nervous when I addressed my stuttering up front. Letting the class, (specifically the professor) know what to expect helps so much. I still stuttered throughout the presentations, but I felt much more comfortable knowing that I addressed it before the presentation. Also, fuck everyone who won’t understand. If you know the information you’re presenting on, just do your best and don’t feel bad when ignorant people don’t understand.