Undergraduate / "How have you Improved the Life of others" MIT prompt. [4]

⦁We seek to develop in each member of our community the ability and passion for working collaboratively for the betterment of humankind. How have you improved the lives of others in your community? (This could be one person or many, at school or at home, in your neighborhood or your state, etc.)(250)

the smile on my sweet grandmother's face

Little hope is enough to maintain a smile.
My grandmother's report says, she has cancer. Although From the first memory of her I hardly see any change on her face, but on that day something was missing from her face, A Hope. I went to see her with my mother and I saw many unfamiliar faces there but I have recognized those eyes, resembling the same hopelessness. I felt something pierced my heart and it was painful, I tried to hide my emotions under silence, I didn't talk to anyone that day. I am sad because my grandmother is suffering but why those people were sad? Who has stolen their smiles?

I took the initiative to start a campaign against cancer. I set up the plan into three different levels: Aware, Unite, Attack. My scout troop has conducted many rallies against tobacco, the major cause of cancer. I received support from local communities and they helped me to spread the idea widely. My fellow classmates helped to raise fund for Cancer aid society and Run for health event was also a big success for us. Later, My troop is nominated for Prime minister award.

My grandmother says, No matter How dark is the night, North star will always be there for help It will never leave traveler alone. I am also a traveler and I believe my grandmother is my North star.

I brought the smile back to my sweet grandmother's face, my greatest achievement.
Please tell about errors and sentence structure flaws.