Don't worry about the speech, what ever happens happens, no sense in worrying about what's out of your control.  But how we react to it is within our control.  We can still smile after.  If you want to get better at it, you'll have to do it more.  No one expects a perfect presenter at first.  Everyone can relate to the fear even if they don't stutter.  What ever the fear, just keep doing it, it's our resistance to things that make it more difficult than it has to be.  Acceptance is easier and eventually the body learns to accept it.  Our bodies are very resilient.  What feels impossible with overbearing fear one time, don't surprised if over time it becomes comfortable or at least easily do-able, even if you may want a vacation, lol :-)