I LOATHE with a passion any form of public speaking.
However, I went on a fantastic course run by my employer - presentation skills. It didn't promise to immediately turn you into a confident public speaker, however what it did was break down a clear and systematic approach to presenting - research and prepare your subject matter - then for the presentaiton itself, have a basic and clear structure - Intro, pre summary, key points, post summary, conclusion reached type thing. Start with bullet points, then do a slide/card per bullet point.
Obviously more to it than that, but it was just a good strategy that meant you would be unlikely to miss anything key out and you would deliver a clear message.
And although i still didn't relish speaking out, at least with a clear tried and tested (rather unoriginal!) methodology, I had a little confidence that at least I might make sense and get my points across...
I would highly highly recommend something like it, just to get through those testing times (I too dreaded such things for days and weeks and would lose sleep about it).
I know people who can just get up and "talk" and talk oh so well about whatever it is. They barely need notes and they make complete sense (and I am rather jealous!) but that will never be me, but I could do it now if I really had to, as long as I knew my subject and had time to research and prepare.
Good luck.