Can someone please help me to proof-read my esay? Thanks!!!!

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?

As a 20-year-old student, I think I had some big changes in my life that other same ages had not gone through. These big changes became the most important experience in my life. However, I am proud of going through those big changes because I grew up a lot after facing these changes. First, I am an immigrant from Hong Kong. I came to America four years ago. I remember I didn't fit in when I first came to America since this is a whole different world than Hong Kong and I had to start all over again. This was a big change in my life and I was very frustrated already. However, I faced the biggest change in my life a little later which I've never expected. My mum divorced with my dad. I moved out with my mum and my younger brother. Since we could not afford to pay off rent and other expenses with only my mum's salary, I started to work part-time since I was in high school. After I finished high school, my mum had left me and my brother here alone and she went back to Hong Kong. This was a turning point in my life because I had to take up more responsibilities than before. Since I could not rely on my mum's financial support anymore, in order to pay off rent and other expenses, I started to work two part time jobs while going to college. Since then, I spend most of my leisure time to work. In addition to that, I also need to take care of the housework since my younger brother won't do them at all. Since I had to deal with my family issues, I didn't get good grades sometimes since I had no time to study for tests. In other words, I took over the responsibilities of a head household. All these created a great pressure on me. I remember I've cried several times because of the pressure. I didn't understand why I had to face these alone. Now when I look back, I knew that I've learnt the most since my mum left me alone. I've learnt something that I didn't find in books. I've learnt that, knowledge can change my life. When I was searching for jobs, I realized that most of the high salary jobs require a degree or proficiency in certain area. I realized how important is earning a degree. Also, if I don't have these experiences, I would not have taught myself how to care myself and become an independent. Also, I would not know how important is to save money. Since I have low income, if I didn't save, I would not have gone through these few years all alone. I think these experiences had prepared me for the new world I will be going soon. In addition, I think I've trained to become a strong individual. I grew up a lot since after going through these experiences. I am responsible for my own since I am an adult already. I've also learnt to look at the good side instead of the bad side whenever something happens. I am more optimistic than before. I am no longer scared of taking new challenges since I want to change my life desperately. Since I have a goal I want to reach, I will not give up so easy. I think these experiences made me became stronger and I am very proud of going through them.