You’re worried that that you got in because of race. All that amounts to is speculation based entirely on fear. It’s not your job to speculate. That’s admissions job. They already did their job and made the decision to let you in. You have an opportunity to work hard and be successful right here and now. You’ll be surprised how much students don’t care. They’re going to be just like any other college student, worrying so much about their physics midterm, they won’t care about stuff like that.