If you write the full speech to remember difficult information, just write this information with a couple of words ("China eats 1/3 world rice" or "laser = population inversion + stimulated emission") or draw a small sketch. When talking, you will just need to find smooth wording given this core information. And yes, you can write or draw this right on your slides.
Alternatively, you can try a mind map.
If you have problems with wordings, you need practice. I like a funny game which you can play with friends: take a blackboard or whiteboard, choose a bizarre topic (e.g. "there is only one true egg in London" or "seasonal migration of flying swine") and make a 5-minute non-stop speech about it. Your speech should include at least 1 graph.
No preparation is allowed. If you stop speaking, you lose. If your speech is not connected to your topic, you also lose. Crazy axioms or premise are welcome, but conclusions should be logical in some way. We call this game "nonsense generator".
Finally, making good presentations always takes time, there is no way you could do it in an hour.