I know I can't do this. Stagefright feels worse than it looks. It is much more noticeable to the speaker. Your audience won't be aware of your nervousness unless YOU tell them. Take a breath if you have to in order to regroup your thoughts.
Pauses are acceptable.
Since you know that there are physical reactions to stage fright, you are also capable of realizing that your mental approach to them can do a lot to help you overcome them. In other words, you should expect to be nervous and have a physical reaction of some kind to that nervousness. Maybe your knees will shake all the way through your speech. If you ignore it, your audience will too. They probably won't even see your knees shake.