Broken Record,
I'm an African American female who can relate to you on pretty much every level, and I have felt a greater sense of burden my entire life. This may have come from my parents who continually reinforced the importance of never taking advantage of your education, and remembering those who struggled during the civil rights era. In my case though, I feel as if it is hindering my ability to properly gauge where I should be applying, and/or, where I can actually get in.
I believe the pressure you're putting on yourself can definitely be attributed to trying to set a high standard as far as gender/ethnicity are concerned. This also is essentially ensuring that you always are at your best, which is a goal everyone in higher education should aspire towards. Good Luck!