I know how you feel. Well back in my Freshmen year in college I was not as prepared compared to other kids in my honors college at MSU for chemistry. I got a 2.5 in both, but since then have gotten at least a 3.0 in all classes, except for a 2.5 in MicroBio.
Now I am taking BioChem and Physio classes, both of which are considered two of five most challenging Undergrad classes at MSU. Both classes are based on a class rank. In a 300 kid class, automatically 25% of the students get a 1.5 or worst. Yeah, and of the 300 students at least 180 are pre-professional students and at least 100 of these students enter the class as some of the smartest kids in their grade at Michigan State.
Due to these classes I am very stressed out b/c even getting a 2.0 in these classes are considered normal, since only 60% of the students in these classes can get a 2.5 or above