Welcome to our DIU forum family, Mr. Noman. This is your first post, and you nicely represented your problem.
Mr. Shah al Mamun sir has already given you nice suggestions. Try to follow it.
Well, I am also a student of BBA department. So, I also faced same problem like you, but I have already recovered this problem. Now a question arises "how"?
Mr. Noman, I am sharing my views here. Listen, when you read any topic, don't memorize it without understand. At first understand the meaning of the topic in Bangla. After that try to write it two or several times in your khata. If you don't understand the topic, please go to your course instructor and understand clearly the topic in Bangla. Don't feel shy. Remember it, our five fingers are not equal. It may be possible that your friend may understand everything without helping of your course instructor.
Wish you all the best.