As a professor for the past two decades, I’d like to share a couple of thoughts.
First, college and university admissions teams admit students they are confident will succeed at their institutions. Your admission was not an oversight or a mistake or some kind of charity. Their job is to choose the best possible institutional matches from among thousands of eager, intelligent, hardworking candidates. They knew what they were doing when they selected you.
Second, the institutions actively support all students throughout their education. They create opportunities for success. Tutoring centers, formalized peer support programs, professor and TA office hours, and more, are all in place to help students succeed. It is absolutely expected that students will struggle in one or more courses, and that’s fine. Take advantage of all the resources that are in place at CMU. They are a great part of the learning experience.
Third, don’t be shy to approach your professors or TAs outside of class. Nearly every student has areas of strength AND areas of weakness, so even (and sometimes especially) the “top” students come in to ask for help at one point or another. We faculty expect this, and we view it as a good thing. It’s the students who don’t doubt themselves, who don’t push themselves beyond their comfort zone, that I see as a bigger worry, because they are looking the other way when things get tough. Reading your post, I KNOW you are going to succeed. After 20+ years of teaching thousands, I can tell you that I’m not worried about you. Your instincts (and follow through) to seek out challenges and to push yourself through them are the first clue. The skill with which you communicate your ideas is another. I have no doubt that you can and will turn your current feelings of concern and insecurity into hard work and success. Will CMU be challenging for you? Yes, probably, and that’s okay. Will it defeat you? Nope, not a chance. Not you.
Lastly, I want to directly address your concern as stated in the title of your post. Colleges and universities, for their own sake, actively want students to pass courses and graduate in a timely manner. They are also generally filled with good people who care. Whether faculty, staff, or administration, the entire reason most of us went into higher education is be a small part of lifting up the generations that follow us. As such, we track course completion and graduation of students, including demographically, to better understand how well we are succeeding at this task. There is no college on the planet that admits unqualified students of color only to watch them fail. I guarantee you were not “only admitted because” you’re black — not even close. You were chosen for your intellectual prowess (1500+ SAT coming out of a substandard high school??? Amazing.) And you were chosen for your work ethic. For your writing skill and ability to express yourself. For deliberately seeking out ways to challenge yourself. I could go on and on. But the bottom line is that you were carefully and purposely selected by a very experienced admissions committee, whose eyes were wide open and who had lots of other options, because YOU are an institutional match.