Good morning Elizabeth!
I'm glad my prior suggestions were helpful. Let's take a look at what you have so far.
When a person helps other (change this to "others") they meet their physical and emotion need (change this to "emotional needs") [/font]. Helping others also brings compassion and compassion equals a better society. As for myself I would like (No more passive tone! Change this from "would like" to "want") to become a doctor to make an impact on each individual patient's life.
My mother is in the health field. During my childhood, she would tend to(remove this) take me with her to her work, and random clinches, hospitals, and offices. (change this to "at random clinics, hospitals, and offices.") Watching my mother and seeing her helping (change this to "help") others really influenced me to want to go into the health (change to "healthcare") field like her. Seeing the people who were sick and ill really made me sympathetic. That motivated me to want to help others. Every time I get that change (change this to "chance") to help others, I get a feeling of accomplishment and gratification from helping others (remove these words to eliminate redundancy; you've already stated this at the beginning of the sentence.).
When I was younger I remember hearing a story about a Japanese girl named Aya Kito. She was diagnosed with a disease called spinocerebellar ataxia at fifteen years old. The disease is where a ...(change this to something like "This disease causes an individual to...") person loses control over their body, but they can retain their mental ability. During the time knowing that her disease has no cure she began to write a diary about her life as a teenage girl along with a degenerative disease, and it got published right after she died. (This can be reworded for more impact. How about something like "Aya knew that there was no cure for her disease; while she was ill she began to write a diary about her life as a teenage firl with a degenerative disease. Unfortunity, she did not get to see it published, as that happened after she died." In her diary she writes about her feeling and the hardship she endures. In 2005 Aya's diary has been (change to "was") made into a Japanese drama called 1 Litre no Namida. (Since this is a title, make sure you either italicize or put in quotations, depending on your required style of citation.) The script is based on the diary Aya kept writing until she could no longer hold a pen. When I watched (insert "the") drama it was really heartbreaking. Hearing bout (change to "about") this during my childhood, (remove this unnecessary comma) and recalling it, (go ahead and put that comma here) [/font] and contrasting it with my experiences [font#FF0000]to now really made me want to be a doctor.(This is confusing. How about reworking it so it reads something like, "...really lit a fire in me to become a doctor" or something to that effect). I want to help people understand why they're (try not to use contractions in scholarly or academic writing) in the situation they're in and guide, and supporting them on their path of happiness. (Needs a little punctuation work. How about something such as, "I want ot help people understand why they are in the situation they are in; I want to be a guide, and support them on their way to happiness.")
As far as the length of your introductory statement, I think it is an appropriate length already. It has a good hook and states your thesis. You could add something about how doctors positively impact society.
In the fourth paragraph, perhaps you could write a little bit about the other things that you would do as a doctor to enhance the quality of life. Many doctors take on other responsibilities outside of the practice; many are researchers, helping develop new treatment techniques and medicines; others head up directorships at their hospitals so that they can ensure the highest quality care for their patients. Do a little bit of research on things like this and see what interests you, and then write a paragraph about it. I'm sure you will find something else that peaks your interest!
I like the changes you have made so far; this is turning into an excellent piece of writing.
Keep up the good work!