Ditto^ I would study off the SAT Blue book, I got an 1840 during the end of my junior year and after reviewing the book and taking 10 practice tests, I got a 2080 this fall, will most likely bump up to a 2150-2200 in january. Besides that, I would spend more time on a select few EC’s that mean much to you/ relate to your field of interest. I would identify as African American on your app too since it applies to you.
chance me back ? 
http://talk.collegeconfidential.com/what-my-chances/1727267-homeless-to-harvard-chance-me-chance-back.html?new=1