Not exactly the same thing, but; I failed my driving test twice before passing on the third attempt. On the first attempt I failed on three counts, on the second attempt I failed on six counts! I thought I was getting worse, not better! But managed to scrape a pass on the third go. So stick with it. (I still maintain that people who pass their driving test first time fluked it!)
You know where you went wrong - too nervous, plus you let a minor matter get to you. There have been comments in the past on the forums about not letting an early mistake get to you. The examiner is looking for competence not brilliance.
I'd agree with DeltaWunWun's comments; make sure you are happy to fly again before going for the test.
Best wishes for the next test. Please persevere; the elation on passing will be so much better with one failure behind you.