Help edit grammar pls

LOL a friend of mine asked me to help edit his paper. I editted it, but English is my ESL also. This is a personal statement to a UC... help pls, thanks in advance.

First Prompt: What is your intended major? Discuss how your interest in the subject developed and describe any experience you have had in the field - such as volunteer work, internships and employment, participation in student organizations and activities - and what you have gained from your involvement.
I determine to be a computer scientist despite the fact that my parents wanted me to be a doctor. I got my first computer when I was fourteen years old. It was a gift from my uncle in a special occasion. He returned to Vietnam from U.S.A the first time after twenty-two years. At that time in Vietnam, having a computer was a luxury. Because computer was one of the most important inventions of the 20th century-- a powerful machine that can do any imaginable things, the gift made me so excited and curious. Therefore, I wanted to know everything about my mysterious machine. As a computer scientist, my uncle taught me basic lessons about computer. He stayed in Vietnam for only one month, but he changed my whole life: I want to be like my uncle. I want to be a computer scientist.
After my uncle came back to the U.S.A, I continued to learn and explore throughout the computer. Eventually I crashed it countless times. I remember the first time I crashed my computer, I freaked out. Nobody was able to help me fix it. Consequently, I went to a library. There I read every book I thought of that could help me. And it took me about three weeks to find out what was wrong with my computer and how to get it fixed. Although fixing it can be tedious, its process allowed me to learn so much about computer from all the books I have read. The more I crash my computer, the better I understand it.
I grew so much interest in computer led me to join after-school-computer-club during my freshmen year in High School. I was lucky having a chance to participate in the rare club because computer was not popular and widely taught in Vietnam at that time. From the club, I learned my first programming language - Pascal. I stayed after school almost every day to practice Pascal.
Despite that my parents wanted me to be a doctor, I decided to go to Bach Khoa University majoring in Computer Science. Bach Khoa University is one of the toughest schools in Vietnam. I took their admission test and I got 27 out of 30 points. However, shortly after I received the test result, my family also received news that my uncle was sponsoring us to the United States, and everything would be done in less than 6 months. Therefore, my parents decided I should spend my time studying English to prepare for a new life in America. Unfortunately, due to some unforeseen difficulties in paperwork, it took us more than two years to come to the U.S.A. In those two years, besides studying English, I took my time to look deeper into computer and self-taught another computer language - programming C++.
When I told my uncle about my dream of becoming a computer scientist, he suggested that I should reconsider my choice because it is getting harder to find a job in this field. Nevertheless, it will not change my mind. I desire to be a computer scientist because I love playing with logic and all the interesting things a computer can do. For this reason, I will do my very best to achieve my dream.
Second prompt: Tell us about a personal quality, talent, accomplishment, contribution or experience that is important to you. What about this quality or accomplishment makes you proud and how does it relate to the person you are?
I am a friendly and outgoing person. I work as a tutor in math, science, and physics fields. Sometimes, I volunteer to help teach older people how to use computer. Despite English is my second language, I manage to be an ‘A' student. My favorite sport is soccer. When I have free time, I play soccer with my friends. Eventually some of them were in my Computer Science class, Java programming, at Evergreen Valley College. We have spent a lot of time studying together in school library. Once, the Computer Science Professor gave us an extra credit problem. My friends and I stayed in the library all day but we could not figure out although the problem was very similar to the homework problem that we had done a week before except for a small different. I went home and decided that I am not going to give up that easily. I realized that I underestimated it; that small change in the problem caused a lot of conflicts to the program. I tried everything I know but I could not sort it out. It felt like I had all the parts of a machine but somehow I could not put them together. I had to e-mail the Professor solution before 6:00 AM in order to get full credit so I decided to stay up a bit late. Since I would have two classes on the next morning, I agreed that if I could not solve this extra credit problem before 1:00 AM, I will go to bed. However, at 1:00 AM, I still did not make any progress. The problem irritated me because it seemed too easy, yet I could not figure it out no matter how I tried coding it. Therefore, I decided to continue.
Two more hours passed by, and the errors kept occurring every time I tested the program. I thought, "Maybe I have been heading toward the wrong direction the whole time." I deleted everything, I tried to forget about the codes of the homework problem, and then I looked at the problem again as a brand new one. It took me about an hour to see it through, and it was totally different from that of the homework. The problem was not too hard, rather a tricky one. Once I figured out the trick, writing the codes was easy.
That problem made me think about it a lot even after I had solved it. It was supposed to be easy, but it gave me too much trouble because my thinking was objective. I underestimated and overlooked the small change in the question. Moreover, the temptation to reuse the codes from the homework blinded me and led me to the wrong direction. Since then, I try to look at every question from as many aspects as I can, and I try not to miss out any small detail that could be important. In life, and especially in computer science, a small detail such as a comma can change the whole program.