Columbia Supplement - Which activity are you most proud of?

Hi guys, please help me proofread my Columbia Supplemental. I would really appreciate it because this is my first draft and I would like some feedback, especially on the grammar (really paranoid bout that). Thank you!

Prompt:In 150 words or fewer, please briefly describe which single activity listed in the Activity section of your application are you most proud of and why?

Having participated in a myriad of activities in high school, I am perhaps still most proud of my very first one: serving as a teen mentor at the local community school. Why? The reason is that the experiences I gained as a teen mentor have allowed me to become the difference maker I am today. Raised in a rather sheltered environment, I was accustomed to relying entirely upon my parents for everything. However, when I began my role as a teen mentor, I was forced to step out of my comfort zone. Suddenly, not only did I have to take care of myself, but also there were now others who had to depend on me. I was to be their role-model now. The various difficulties I learned to overcome in my unfamiliar position have engraved me into someone with perseverance, determination, and most importantly, a passion for helping others.

T.Z. I think you need to explain what you mean exactly by your role as a difference maker. is that a term exclusive to the group you were mentoring in? Since the term can connote many definitions, you should be sure to explain what that role is and how you enforced it as a teen mentor. Since you are very proud of this activity, try to present a situation that would help the reviewer visualize the kind of action that you had to take as a teen mentor and why it would result in your becoming a difference maker in the group.

You can remove the introduction that you currently have in order to make more space for the explanation about your teen mentoring. If you immediately start with I am perhaps still most proud of my very first one: serving as a teen mentor at the local community school then follow it up immediately with the experiences I gained as a teen mentor have allowed me to become the difference maker I am today. then you will be able to allot more space for your role development in the group. This will further strengthen your response to the prompt.

Perhaps take out the "Why?" and simply answer that with the next sentence which can be significantly cut down to go straight to the point.

Also, add some examples of your experiences to further support how you've become the difference maker you are today (and also how you're a difference maker through examples).

The connection between the dependence you have on your parents and the dependence the students have on you needed slight improvements. How and why did you need to learn to take care of yourself in order to mentor others? Maybe elaborate more on how depending on your parents had an impact on your need to become a mentor.

havechange to has you still volunteer at the community school, I'm assuming?
I would also just include a short sentence about a person at the community school who really defined your time there
I think your connection to your parents is a little confusing, I personally do not think it is needed.
Overall it is a good personal statement, just a little more elaboration.