This is how I was in my last year of High School, except I ended up getting above a 90 average for the whole term haha. Only thing that brought me down was a 78 in Chemistry; everything else was 90 and above (including 95 in Calculus, 98 in English and 99 in Physical Education)
You need to get off the base and work harder to achieve that goal. It does sound like you're purposely bashing your grade so people can comment on it saying how good it is so you'll feel better. Whether those grades are real or not... idk.
I'm white and anything less than an A brings great dishonor to myself and family.
Also this thread seems like a humblebrag. The most likely answer, is that you probably should have been more strategic in preparing for your tests, even if minorly moreso.
B's are usually working hard, but A's are working both hard and smart. Unfortunately you ended up on the wrong end of the dividing line this time.