Storythings pointed at this Clive Thompson piece: You don't have writer's block, you have "reporter's block".
It resonated because I was chatting with someone yesterday and was reminded that one of the best way of conquering nerves with a presentation is to do more work. Do more research. Know the topic better.
A lot of organisation set people up to fail when presenting by asking them to talk about something they only understand superficially. This is particularly the case in agencies, consultancies and the like: that's part of the job, to become convincing in an unreasonably quick time. That's a useful skill to learn but it's not a recipe for anxiety-less presenting and it's not a good way for most people to think about their presenting life. And it's a diversity issue.
Your PowerPoint structure can help you organise that knowledge, make sure you're not just sharing proof of work. But feeling bullet-proof about the topic is a great way to feel more comfortable.