Undergraduate / The most important decision that I have ever made was to study in U.S as an international student. [3]

"Everyone has made a decision that has changed his or her life, and those decisions will always swapped one's destiny in a way or another."

- Use the word 'sway ' instead of 'swapped'.
- "in one way or another" instead of 'a way '

"Therefore, we try our best to be near enough of the perfect choice."
- Not sure what you mean here. I don't think 'near' is the right word choice.

"However, from time to time, it turned out to be a regretting decision "
- ... it turns out to be a decision one regrets .

"As for me, I have also made some decisions since I' am no longer the immature high school boy. "
- Take this sentence out completely.

"I have also built up my self of confidence, and experience to face the most influential decision in my entire life.
- Take out the word 'also '.
- "and experience in order to face..."
- "of my entire life" use the word 'of' instead of "in "

"The most important decision that I have ever made was to study in U.S as an international student."
-"study in the United States ..."

I'll get back to you soon with the rest of my suggested edits for your essay. Good job on the essay as a whole.