@cleon19 I remember when the thread posted by @intparent was active last fall. The most important thing I got out of it was this short ebook:
http://www.■■■■■■■■■■■■■■■■■■■■■■■/uploads/1/0/9/5/109505679/hack_the_college_essay_2017.pdf
It’s only about 30 pages of actual text. My son said it helped him find his voice. He reread it several times as he was writing his common app and scholarship essays. He also really liked On Writing Well by William Zinsser. His absolute favorite writing book.
Good luck, and keep plugging away. You’re doing great starting so early.