First, I found myself a very weak person.

>>Correct

Looking back, I had so much confidence before that and may be I was arrogant.

>> Looking back, I had so much confidence before that, and maybe I was arrogant.

But after I went through the failure, I found out that I overestimated myself and I also found myself a very vulnerable person to failure and a very weak person. Second, I was able to grasp my weaknesses naturally.

>>Correct

From past failures, I was able to work out what went wrong and what I did wrong so that I could practice preparing myself in advance.

OR

>> From previous failures, I learned to determine what went wrong and what I did wrong, allowing me to practice preparing myself ahead of time.

At the same time, I naturally identified my weaknesses and made more efforts to differentiate myself from other candidates.

OR

>> At the same time, I recognized my flaws and increased my efforts to set apart myself from other candidates.

Third, I learned how to overcome my failure.

Honestly, I didn't go through things that could be called failures, but when I went through failures, I didn't know how to overcome them.

>>Correct

However, after experiencing various failures, there were many examples of what to do in this situation and what to do in that situation, and I created tutorials on how to deal with each situation and how to overcome them.

OR

 >> However, after a number of failures in a variety of circumstances, I developed guidelines for dealing with and overcoming each problem.