Don't quit at all. You are already prepared, just need to revise your subjects. What if luck favors you in your 2nd attempt? You will feel really great then. And don't worry even the toppers fail in this particular exam. A group of doctors studied hard for CE-2013 and believe me all of them failed it. They were from the same batch in a renowned medical university. Actually when you put your efforts in something then the only thing left is the luck which decides one's fate. So be hopeful and surely go for CE-2013 attempt.
I advised considering you my sister.
Good luck.

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"Whomever Allah guides, no one can misguide, and whomever Allah misguides, no one can guide." Al-Qura'an.