Please help with essay revision

Hi,
I am applying for a scholarship and have to write an essay for it. Can you guys please give me a feedback on my writing, rate it, give suggestion, and help me to correct any error if possible. Thank you !

DISCUSS YOUR COMMITMENT TO PURSUING A TEACHING CAREER AND TEACHING IN A HIGH NEEDS SCHOOL, ACADEMIC PERFORMANCE, EXTRACURRICULAR ACTIVITIES, PARTICIPATION IN SCIENCE AND MATHEMATICS, EDUCATIONAL AND CAREER GOALS.
I didn’t go through the usual route of majoring in education, although teaching was always my calling. I started college majoring in Mathematics and Education, but I changed my major to Pre-Med after my sophomore year because I wanted to be in the same field as my group of close friends and my ex-girlfriend at the time. Most of us believed that teachers do not make a good living, whereas doctors or dentists are almost guaranteed to have a prosperous life. I was never into biological science but I did manage to get in dental school. However, I dropped out the dental program after two years and went to work in the biology field. But, I wasn’t happy with what I was doing, so I decided to change career by opened up a business in photography. I was not in love with my business either, but it made good money and because I had put so much money in it I had to hang on. I had two photography shops for over six years before I closed them down because the new digital photography technology came out and killed the whole traditional film photography industry. But even when I was doing well with my photography business, I still tried to find time to teach on the side, because that was what made me happy. It's hard to describe why I want to be a teacher, but my heart tells me that teaching is what I am meant to do. I have taught and tutored since I was in high school, and it was always my comfort zone, a job I could always fall back to make some extra cash. Although the teaching profession doesn’t get rewarded financially, but to me it is a noble profession because teachers are helping to grow the minds of the next generation. It would be heart fulfilling when you can make a difference in one’s life, and to me it is far more valuable than reward of recognition or money.
I came to this country as a refugee and I am always been thankful for all the things and opportunities that this country had given me. It is my obligation to do something to repay what I have owed. Becoming a teacher and teach children come from a high needs schools is probably the best way to make a contribution to society. I totally understand and expect to encounter with a plethora of challenges to work for a school which is taking place in an area where poverty, violence, cultural diversity and multitude of languages occur. I believe that to teach in poverty areas, a teacher should understand that he needs the best preparation and mentoring because the difficulties that he will face will multiply. I recognize that the majority of these minority and low-income children come from families where the parents are most often holding more than one job in order to support the family. Because of that most parents are unable to be actively involved in the child’s education, so the teacher is forced to take the role of the parents as well. These minority students need dedicated teacher who care and believe they can and will learn if properly taught. They need a teacher who can understand the types of homes and cultures from which they come. These students need to be inspired and supported to bolster their confidence. I set a goal to continuous learning to become a successful teacher. It takes vision, hard work, focus, planning, and above all, dedication to be successful. Be able to handle the everyday pressure of a difficult job is also essential, because most poverty schools teachers often face stress, insecurity and fatigue when they try to rise above the challenges and to educate their students. If I can be successful in guiding these children on the right path for a brighter future, the experience is one of the most valuable and exciting endeavors I will ever undertake. It would be a lifetime heart-warming.
So the question is why do I want to pursue a teaching career and teaching in a high needs school? Well, I have been through the ups and downs in life; I was lost, confused, and made mistakes with my career direction so I want to use my life experiences to guide the future generation on the right track. It is my obligation to pay back what I have owed from others when I first came to this country. It is my passion and personal satisfaction because I feel happy when I teach. These reasons are the combined drive that motivates me to push for a teacher credential in which I should have done when I started college.