Re: i wonder
Your basic problem is that you are careless, this problem doesn't let you study properly. First, try to make a proper Timetable strickly follow it. Just keep that time in your mind when all your assignment will be done and you would be mentally relaxed, just feel that relaxation in your mind then study.
Drink lequids like water juices as much as you can, it will keep you fresh. Try to make the environment for study. Don't get panic and worried for your work, too much worry make the careless people (like me) even more careless lol.