I agree with the others, do not throw in the towel. If you think that you need a bit more time, ask them when the next class begins, and start that time instead. However, keep in mind, nursing programs
are run far different from this; they are not as flexible. People would have to wait an entire semester, or even a whole year to repeat a course, and they are strict on absences. They feel that the nurse should come in prepared at all times, under any circumstances. Nursing school will be much different than the pre-requisites you are taking.
With that in mind, know that we all make mistakes, we all react to stress and there will be bad days. And, we all doubt ourselves, even after being a nurse, if we did the right thing, could we have done better, etc. Those feelings are completely normal.