How are you studying?
On the one hand, there is understanding and, on the other hand there is drill. You can understand how to do a certain kind of problem but if you haven't drilled at doing it, you will slowly stumble through it on tests. You can drill at doing a certain kind of problem and not understanding what you're doing. Then any slight change or probing question that might happen will throw you. You have to balance these types of learning.
People have different speed limits for their algebraic calculations. Do you write them down too quickly in a scribbly manner, all over the page and make errors because of that? Some calculations require a degree of imagination. If you always think there is only one way to go to the next step in a calculation, you aren't using your imagination enough.
There are (at least) two different ways of remembering material. You can simply go over it and trust that a normal, intelligent person will recall things that he understood. Or you can remember things like a child - use songs, rhymes, repeated phrases. If you are agitated and lacking self confidence, remembering things like a child is going to work best. Just be careful that when you make up songs or phrases that you state the facts correctly. (You might also read books on memory and look into the ancient memory technique of building "mental cathedrals" - I've never tried that myself).
Other things I tried myself are mentioned in the thread:
Physics Forums > PF Lounge > General Discussion
Subliminal Learning While You Sleep & Other Inventive Learning Methods