Well, it'll get a slightly weary chuckle, won't it?
The trouble is that unaccustomed as I am to public speaking misses the point completely because a speech isn't about the speaker, accustomed or not, but about the audience.
The audience isn't there to watch the speaker show off, they're there to benefit in some way from the speaker's message. A speech is for sharing something. It's not a lecture - although, actually, the best lectures consist of sharing something, too.
Oh, and being reasonably sober will probably help, too.
William Jennings Bryan: American Presidential Campaign 1896 (just look at how inspired the men on the stage with him are). Bryan was a very practised speaker, but never became president.
Thing To Do Today: make a speech. This word has hardly changed since the English language first emerged from the swamps. It comes from the Old English spēc, and is related to specan, to speak.