If it gives you any comfort, just remember that people probably won't remember your speech a year later and that it won't have a huge impact. So it really isn't anything to stress over.
Liz has some nice advice, too, if your speech is long. Same with what Mr. Simons said, if you can cut out a lot of the nervous tics than you'll be better off.
I don't have any issues with public speaking so I can't relate super well, but I sympathize with those who do find it challenging