As a uni lecturer, I give at least one lecture to 50+ students every week. Let me tell you this, what you have to do is go in there with a mindset of "If I stutter, I stutter. If I don't, that's great. But in the end, I will give it all I have." Believe me, this is a great experience towards improving your speech, either way you perform. When I started lecturing, I used to worry about what my students thought. I see a smile here and there and think to myself, oh itms because I stutter. Absolutely not true. Most people really don't care about our stuttering and if they do, so what. You do what you do and excel at it. Hope you have the greatest lecture of all time.