Its just nerves. I was absolutly terrorfied when it came to taking my college level math course for a number of reasons. I've always been terrible at math, and for some reason I took it the last semester of college, with 3 other classes. Meaning, if i failed, i had to find a new place to live, get another school loan, find a new job, and spend another semester in a town 300 miles from my home for 1 class.
Of course the first day of class didnt help, going over the syllabus of material which was completly foriegn to me, and to make things worse, I sat next to 2 chics whom, through conversation (failed attempt at mac'in), learned that they were both math majors who had failed the class the semester before.
Then after the first few classes I realized that my fears were unfounded. It was no different then any other college course. Do the assignments, the homework, reading, studying, ect and its as easy as a freshman level "survey" class.
I actually grew to love that class, and knowing that i sucked at math, did extra assignments on my own, the math problems eventually became challenging and fun, like a puzzle for the mind. Eventually i realized that it wasnt hard at all, it was irrational fear which left me thinking the worst after every test I would think to myself, "fail, i know i failed" only to return the next class and find that I recieved the top scores on every test except 1 (our teacher would show the top score, average, and lowest, without names, in a powerpoint)