Undergraduate / Common App-influential person of your life (my grandfather) [7]

hello, this is my first time posting my essay in here, and please help me with this.
I am a chinese who just moved to United States for 2 years, so please don't mock at my poor writing skill lol
Every comment will be great. Thank you guys for helping.
I really need your help, because I am not sure if that is good enough to apply.

here is my essay

When I was a child, my parents spent most of the time at work, so I usually stayed with my grand parents. Because of this, my grandfather influenced me very deeply. He was a busy man, and always had something to do, but he would always have time to help me. He taught me lots of thing that influenced me for the rest of my life and I always aspired to be a person like him. He told me to be honest, just, and brave when facing everything. He once told me that "A person will never success if he has a weak mind," I believe he wanted me to be courageous when confronting obstacles. Although I was a little child at the time, from his tone of speaking, I still understood that he wanted me to be successful, but it has been difficult for me to live up to his standards.

When I entered the third grade, my mom transferred me to a new school. She said it was better for me to be in a private school. I felt intimidated by the new school because I didn't have any friends there and the teachers were very strict with students. Everyday I went to school, I didn't talk too much, and slept during the classes most of the time. I naively thought that if I did poorly enough I could go back to my former school. My grade went down instantly, and after he saw my report card, my grandfather was very angry and reprimanded me severely. He said "How dare you did this? Did you forget how I taught you to do?" I was frustrated, and I still remember every single word he said clearly. Several days later, he calmed himself and said "You shouldn't start anything before you are prepared really well. Once you start it, you get to be the best, or you don't want to waste your time on that." Do nothing or do the best.

At the moment, I felt shame about the things I had done. I felt that I had to change myself in some way. I had to be the best. I went to school earlier everyday to spend extra time studying the day's lesson. In class, I concentrated and tried to understand every detail the teachers had taught. After school, I studied hard and previewed the chapters that I was going to learn the nest day. I hoped this could help me to achieve grandfather's wishes and impress him, but this was not easy to do. My classmates, who studied all the time, had much better grades than mine. I knew that I had fallen behind. When I wanted to surrender again, my grandfather's resonant voice came to my mind: "Do nothing or do the best." Apparently, that was I should do. A semester later, I had the best grades in the whole class and the third best in my school. I went to grandfather and cautiously gave him my report card. He took it and put it to the side without even look it. I felt so bad and felt all my efforts to get good grades had been for nothing. "Here is my grandson," he said. I looked at him, and he said "I know you are the best one." After that day, I knew grandfather felt proud of me and he knew I found the way I should be. I was really thankful for his lessons that drove me to become a better, stronger person.

I have several questions about my essay
1. Is this one too long or too short?
2. Are there many grammer errors or spelling problems?
3. Are there any better words to use instead of what I already have?
4. Is this one really fit to what they want me to write?
5. Is it good flowing or sounds weird?

I really appreciate your helps.