How to write motivational letter.

Hello, i am planning to apply for college for the next year and i am writing my motivational letter please can u see the draft of my motivational letter and give me an idea to improve it thanks

Dear Sir/Madam

I am very pleased to write this letter for IMRD program. I was born from the family who has a very low and limited income in north Ethiopia. Since I was little I was very interested and good in my education and I was from the front runner in my class .I have received many encouraging certificates and prizes from the school I was learning since I stood one to three in every classes of mine. I am the second child and the only girl in my family. Since my parents are not educated I was making most of my educational decisions by my self and I am good at it .I am very bright, fast learner and can carry a lot of burden and have the ability to solve problems.
Upon my completion of my high school education I joined the agriculture faculty of Haramaya University (formerly known as Alemaya University) in 2004.I was one of a very competitive and hard working students from my department. I graduated in 2008 to major in the field of plant Sciences. I was very interested to the field because I have believed that the field can help me to contribute my effort for the development and also to give sustainable food security for the population of my country which the economy is dependant on agriculture. Immediately after my graduation I joined one of agricultural organization (Pro-Poor) as an agronomist .I have been satisfied to work in the organization, as it's main goal is to enhance food security at a house hold level. As we know more than 70% of my country is rural areas which need professionals who have knowledge to develop and show the way to get a better life for those communities who is living in miserable condition.
However it is difficult to bring about sustainable change for the livelihood of the community with the limited knowledge I have. Governmental and Non-Governmental organizations have made a lot in bringing about development in every sector in the country. However nothing has changed in the country due to lack of skilled man power on development fields particularly of women. I believe that, this all made the country to be counted as the poorest and the least developing country in the world.
I am sure If I got the opportunity to study in your program I can address and change many lives in my country and I have a very big vision and interest since my childhood to change my country's situation through the knowledge I can acquire from my education.
Therefore I am highly motivated to continue my Msc education in the field of rural development, in which I believe that it can contribute a lot for a stated problem in my country.
I will be very grateful, if IMRD gives me the chance to be one of the students of rural development.