First essay

Hello,
I take writing classes, and today I have read my first essay in the class. Teacher smashed my essay in pieces. I am not native speaker, and most of my errors were because of this.
Before writing essays the teacher gave us structure of essay, which should consist of 5 paragraph: intro, body (3 paragraphs) and conclusion.
Here is my essay without corrections:

"The Three Most Important People in My Life

First of all, I would like to define what does expression “the most important people” means to me. I think the most important is person who has the greatest influence on you, develops your outlook, who at certain point somehow changes all your life, or whom you regard as role model. Of course, at different stages of my life I’ve had my own ideals, my role models, and there were much more than three people. But I am going to tell only about the three most important people in my life.
I am sure that 9 people out of 10, responding to question “Who is the most important person in your life?” would say “My mother.” And there are right because besides the fact that mother gives life to her children, she is first one who teaches them how live in this world, how behave in the society. She is first role model for them. I am not exception from this rule, and, like the others, I learned everything that I know from my mother. She taught me what is good and what is bad, what is most valuable in human relations. Setting an example, she taught me traditions and customs of my people, respect to the other nations.
Another very important person in my life is my sister. Although we lived separately, we had always been together until last year when I left for America. She has always given support to me with her ability to listen to my problems, give an advice when I need it, make laugh when I am sad, and in spite of the fact that she is very far from me she continues doing it.
When I was about 14, it was very hard time for me and especially for my parents. Like a lot of teenagers, I was awful – I answered back my parents, did not pay attention to their advices and rebukes, and considered myself cleverest person in the world. At that point, I ran against Dale Carnegie’s book “How to Win Friends and Influence People.” I discovered very interesting thoughts such as: “Smile,” “Try honestly to see things from the other person's point of view,” “Show respect for the other person's opinions,” etc., that really had a great influence on me and changed my attitude.
As I mentioned above, I have had a lot of people who had an influence on me, whose life and works somehow attracted me, whom I wanted to resemble, who changed my world view. There were writers, philosophers, actors, musicians, and even some ordinary people among them. I am grateful to all of them for filling my life with sense, and I hope I will meet this kind of people more than once in future."

Besides misusing articles and having too long sentences, with which I strongly agree, the teacher made next corrections:
1. I didn't give thesis. At the end of Introduction I should have written: "The three most important people in my life are my mother, sister and Dale Carnegie."
2. In the 3rd paragraph he pointed at several defects:
a. lack of unity
b. I shouldn't have written about myself so much, because in this essay I had to write about the most important people in my life, and nobody is interested in my person
c. Mention of Dale Carnegie doesn't make sence, because in the first two paragraphs I wrote about my relatives, and it would be better to make up something instead of writing about him
d. They don't use "ran against" in English
e. Never use "etc.", it's discourtesy
3. In Conclusion:
a. they never use "As I mentioned above" in English writing
b. writing "There were writers,..." sentence in Conclusion, I brought up new idea in essay that intolerable. I should have written again about my mother, sister and Dale Carnegie.

What do you think about it? I will appreciate all responds.