What's the essay prompt?
For the most part, your usage is fine. Most of the mistakes I caught wouldn't have been noticed by admissions readers.
I'm not an average senior in High School.
Don't capitalize "high school."
epitome of people
You can't be the epitome of "people." Ideas, not people, are epitomized.
the war and it's
There's no apostrophe in this form of "its."
I'm a seventeen year homosexual
Hyphenate "seventeen year" and than add the word "old."
safe, until
no comma
made me acknowledge with a fact that I was aware of but was also in denial of
Do you mean...
forced me to acknowledge a fact of which I was aware but that I had denied ?
safe, until
no comma here
person who I'd always
"Who" is redundant. All people are "whos."
There may be a couple more, but mostly these are pretty subtle errors.
Stylistically, there are a couple more serious issues. Whether you want them solved depends on how important this paper is.