When you stand in front of the class, be 7 foot tall. You own that room while you are presenting. Fill the space. Standing there, immobile in front of the class, is the worst. Move around. Watch how your teachers use the classroom. Emulate the best of their behaviors. Want a brief respite from being in front of everyone? Walk to the back of the room as you present. That whole room belongs to you. Use it. You can't live back there though. ;) Get access to the room before hand. Practice your presentation in that space. You got this. Enjoy it. Probably no way to get around the fact that you will stutter. Might as well do it with style and confidence.