Ah, yes! The most devastating struggle putting together a speech. The way I handle orals is that I first read through the entire script word for word a couple of times, taking a little break to consolidate, then returning to try a new method.
Upon second stage, I try to read ahead of the script whilst still talking at the correct line; skimreading and taking out the key points to jog my memory. You will stammer and stumble a lot, that’s fine. It’s all part of consolidation.
Continue to do this until you can basically physically act out performing your speech to the audience, only darting your eyes briefly to your script yet still speaking and gesticulating fluently.
Once you are doing fantastic at that, you can do one of two things, although the first requires a lot of skill and natural talent to orate. You can continue to do this until everything sticks in your head and you don’t even require a script. This is extremely rare to do, but I have met people and even given a speech without using a script or cue card once. Leading on from cue cards, the second and most common way in the third stage is to -you guessed it- use cue cards. Write down very briefly the key points of the script, and carry them through to the speech. Get comfortable using the new medium until you can effectively get through 90-95% of your speech without veering far off topic or stumbling over a lack of preparation.
That should be enough to deliver an enjoyable speech fit for a good mark.