I completely forgot the words in my speech. Every time I am under the stage, I am fully prepared, and I forget it when I go on stage. How can I overcome this problem?

This is normal, because when people are nervous, their minds will be blank, especially on the stage, when there are many people under the stage, this situation will be more. First of all, to overcome this fear, you can only recite your speech well, which is the most basic. Secondly, when you go on stage, you can try to take a deep breath, speak slowly, don't worry, step by step, which will make it easier to remember your lines. Anyway, this thing will be skilled with more practice. Try a few more times, it should be no problem. Another way is, if you can show it on PPT, but you can try to uninstall the keywords on PPT, it will be much easier! I hope I can help you!