Figure out what your anxious about and flip it. This isn't the first time you presented, so everyone probably knows you have a stutter. You have nothing to hid. Know that everyone is anxious about presenting, not just you. Theres probably some kid in your class thats even more anxious than you. Some kid makes fun of you? Know that your instantly better than them because your facing a fear and fighting an adversity thats gonna make you a stronger person than them. In return laugh at that kid because he's an asshole with a shitty character and personality. I'd rather stutter than have that. View your stutter as a grind stone thats gonna turn you into a diamond some day. :)