I had done a few bits of public speaking and was always very nervous. I was then sent on a course by one job - it was various things on team work and organisation. Two things came from that:
1. There was a girl on our team who just kept saying "I'm useless at this I can't do it." We made her practice and practice and each time she did a fluff yelled "don't stop, keep going". Her actual talk in front of all the groups was not very good - wooden, stared at the clock, but she kept going from beginning to end, didn't fluff, didn't run out the room. "Her" group - us, told her how well she'd done compared to the practice sessions and pointed out that she had not made a fool of herself. No idea what happened to her, if she went on to better performances, but what she put over was perfectly acceptable and non-embarrassing - dull, but absolutely fine.
2. They video'd the presentations. I was very nervous, especially of being video'd. Did my best, thought I'd done OK - not waved my hands around, spoke clearly, remembered to look around the audience from time to time, all the things we'd been taught, but I thought it was obvious I was nervous. No it wasn't. On the video I was absolutely fine, looked much better than it had felt from the inside, and after that it has always been easier. Not a doddle, but OK.
So I'd recommend giving a practice speech to a video camera, to a couple of friends and a video camera.
Also have a few stock phrases ready for questions - if you don't know the answer, can you send it through afterwards? As in just say "I don't know the answer to that one, but I can get it for you, would you like to leave your details afterwards?"
Incidentally, one of Maureen Lipmann's humorous autobiography books - she was in a costume drama in a West End theatre. She is short sighted. She has never worn glasses on stage - and couldn't when in period costume anyway. She gets fitted for contact lenses and wears them on stage for the evening performance - and could see every face in the audience WATCHING HER. It was no longer a friendly audience blur, they were people WATCHING HER. Terrible stage fright and as soon as she could get into the wings and take out the contact lenses, she did.