Practicing your presentation will help with pacing, timing, and easing your nerves.
While you practice, notice what you do with your body, too:
Think through these ahead of time:
Just as you have done with attention to detail in your slide and writing, be intentional with how you speak.
Breathe into your belly. Pause to breathe when you need to. This will help your volume and pacing.
Enunciate your words. Build in pauses. Your clarity and pace will help your audience listen and think.