I speak publicly every week (I'm a minister).
Lots of good ideas here. I can't emphasize enough the practice part. Work from your script, but actually read it out loud and adjust your script as necessary to get it "talkable." We don't write and speak the same way, as a general rule. So make your script sound like you're speaking it.
Second, consider writing your pauses into your script. Anytime I think I'll need an extra-long pause to let what I just said sink in, I put in my script "..." Or instead of one line between two paragraphs of my script, I'll put a couple. I also sometimes write in any particularly meaningful hand gestures as a note to myself, just in brackets (gesture widely).
Another suggestion, is to print your script in nice large text. And to adjust the spacing so that you don't have a page turn mid-sentence/mid-paragraph. Bonus points if you have a page turn at a point when you needed a meaningful pause anyway! That way, you minimize awkward pauses when you shouldn't have them, and have a built-in pause for yourself when you should have one.
Re: speed, not much helps other than practice, and feedback. Feedback can be from a trusted friend, or from recording yourself and listening to it. Remember that you know the material, they don't, so they need time to process what you have to say. In some of the places I speak, there's almost a discernable echo, and if you're presenting in a large and echo-y place, you may find the same. In which case, you need to slow down even more. And if you'll be speaking with a microphone, that brings its own challenges, and you should absolutely practice your presentation with a mike, if at all possible.
Keeping working at it, and I hope and pray that it will go well for you!
