That is solid thinking. Running would only build anxiety and make things worse when you next need to do it. I give talks to groups of people. I practice the shit out each one. When presenting, I am doing 10 trial runs. I am figuring out what I want to say and how to say it concisely. When talking, this helps me go into autopilot. I think about the worst thing that could happen. For me, the worst thing would be to struggle and give up. I would say I can't do it today, and I will send round a recording. My colleagues would respect my struggle. The best thing would be if I present like Obama talks. I think my manager would request a drugs test. Realistically, when I give a talk or presentation, I will stutter. But I will get it done, and people will leave with valuable information. I will have achieved my goal. This is all that matters. When I do something once, I can do it better next time and keep improving. Personally, I start all talks saying that I have a stutter. I find it takes the pressure off. I wish you the best of luck. I bet you smash it. Also, there are likely going to be several nervous wrecks in your class who will duck out or give a poor presentation. We ain't alone.