Undergraduate / commonapp essay- elaborate an activity- tutor [3]

Hi. I'm an international student, so I specially worry about my essay. Could you read my essay and give me advices to improve it?

The images of ragged boys selling newspapers in my street obsessed me many days and urged me to do something to help them. I immediately registered to be a volunteer tutor teaching street children in my district.

On first days, teaching was not easy as I thought. I remember a number of times I annoyed when they did not finish exercises, lost their books and even was absent from my class. However, as I understood their difficulties, there are only empathy and admiring I felt for them. It encouraged me to try my best to teach them knowledge, give them advices, and become their true friend.

Now, after a long time of teaching, I only felt happy when recalling their warmly greeting faces, the name "Big Brother "they called me and their interesting questions they incessantly asked about life. Helping these children taught me how to appreciate what I have, how to stand on my own feet, and especially, how to share with other people.