The small embarrassing moments in life are the ones that make us laugh and cry. I have done countless embarrassing things in my life, and when I look back I have to laugh ["about it" is a really weird way to phrase it], because most of them are extremely foolish acts by me that back fired on me [because most of them were extremely foolish acts that tended to backfire on me]. [The second me in your original sentence was also redundant since you've already claimed ownership with the first me].
Every break in school, my friends and I walked through that same corridor, where the science labs were, that lead to the field. That day, however, was different. It still plays in my memory like a video.
My friends and I were joking and laughing around, and as a ‘joke’, my friend shoved me. Never did I think that such ["a" is redundant] little force would put me on the spot. Due to all the bags that were scattered on the floor, I stumbled and fell on top of someone.
I was [overuse of the word "extremely"] ashamed to look at who it was, but I remember seeing some seniors standing there. My so called friends were laughing while trying to help me up.
I will never forget how mortified I was. Later on finding out that [word "out" made no sense here] all the people I dived on to the head boy made my situation hundred times worst. From that day on I couldn't look at him straight in the face.
[Use "Later on" way too much] My friends mimicked me throughout the entire break, which made me trip again. This time, however, it was just flat surface. According to my friends, it was only possible for me to topple over nothing.
The events that took place are still discussed when I speak with my friends. We all ["have is weird and doesn't belong] laugh about this situation. How such a stupid act was only possible by me. At that moment, it was quite / really embarrassing for me but now even I have to laugh. These small moments in our life are what make it interesting.
Hope I helped. I didn't get everything mainly because of weird phrasing. Try re-reading and stuff. I did most of the work though, so good luck!
- For Teachers