the script of a speech

Good morning ladies and gentlemen!
I’m …from…
And today I’d like to talk about “Change Changing the unchangeable”.
Nearly all of my teachers have told me:You should be more confident. No matter if it is in class or communicating in private ly,I always seem timid gave them a sense of timidity.
I still remember, in middle school, my head teacher gave me a lot of chances to express myself in class. But…I didn’t know what I was thinking at that moment. My brain suddenly stopped running, it was standing still, and saying nothing waswere the only things I could do. After several times trying, nothing changed. It seems to be an unchangeable personality trait I haveof I. Otherwise, I should have been able to change d.
Even when I got this topic, I still had no confidence that I could do it well confident to do it well. But when I tried to work out the composition of the speech, I realized that what made it difficult for me to change my confidence was that I could not change my mind. I have never made up my mind to change. I even believed that thisthe change was unchangeable without doubt.
So, what I want to express is that what we should change is the mindset of thinking something is unchangeable of “unchangeable” itself. Once we try to change, we may find that the unchangeable is easy to change, just like turning around.
Thank you so much for listening.
P.S It's for a English speech competition. I'd appreciate so much your help!

Vocabulary was good. Just a few grammar things really. Let me know if you want me to explain anything I changed.