Ok, my friend, I was in your spot at one time, I found myself to significantly improve in maths from back in the day, when I was truly a monster. It seems to me you are cramming for a final examination perhaps. You've posted a many topics ranging from various form for the reason you stated, but the best thing you can do right now is take a break, go outside for a minute, open your mind to fresh air. Come back in, and for a few minutes evaluate to YOU what your weak points are in the course, assess them, and study each one intently, without jumping around from topic to topic causing your mind to be in a constant flutter of mathematical terms, Sorry to be of no use to your post. Mr. F warn me if need be.