Expression of Interest Letter

I was waitlisted at Boston College. I need an expression of interest letter that would make the choose me from the waitlist. I have a 4.5 GPA, Student Council President. over 20 hrs a week of volunteer work, while also working 20 hrs a week at a part-time job. I'm dedicated to philanthropy work and would love the opportunity to attend Boston College. I come from a low income abusive family situation and NEED to get into Boston College