I am a student, so I understand what you're going through. I believe a few things happened:

• You UNDERESTIMATED the exam because you felt so good. Do NOT let your high vibration and good feeling make you cocky about the exam. You must maintain your HUMILITY. Or rather feel cocky and confident in your ABILITY to study, stay focused, retain information, etc during each study session. Only when its time to sit down, take out your pencil and write should you start feeling cocky and confident about the actual test. Not before. Stay humble.
• Do not become attached to the end result. Which is hard to understand. It took me a few years to understand it in terms of school, but the longer I stayed in school and screwed up my GPA, the more I realized that there is always a "way out". A different route to take for those who don't achieve the 4.0. It depends on you and having faith that you can achieve the life you want no matter what. In the present moment, you WANT to do well on the test. So go for what you want the best way you can! But do not be attached to the end result. Try to get to a place where if you don't get what you want, you don't feel devastated. Again, this took some practice and majorly screwing up my academics for me to understand it. I wonder if it is possible to learn this "the easy way"? lol But once I stopped being attached, I started making good grades, got accepted into grad school, etc.
• Find a test bank. There are students in every class who have access to past papers, past exams, past notes, past SOMETHING. Find them and use those things because it will reduce your study time and anxiety in half. ;)
• Reassess your study technique. I'm in the process of finding my "perfect" study technique, too. But I do believe that the best way to study is to answer QUESTIONS about the material. It forces your brain to understand the material in multiple ways. Use the questions from the textbook. My professors have ALWAYS had questions that are similar to what's in the text book -- even if they don't use it! I guess there is some universal language of testing for each subject, lol. So my brain automatically knew what to do to answer it. I use a method called "Guaranteed 4.0" (message me at quitejaded at gmail if you want to see it or just google it) to help me memorize and understand the information and then when its time for the test, I answer as many text book questions as I can. Ace in the hole!

OK, buddy. Hope that helps a lot! Keep in touch. :)

You gave a clue that you did not feel good post-exam. I am thinking perhaps you were not prepared for the exam? If you accept that we are spiritual beings living a human existence, we still have to obey the physical laws, which means in your instance, you had to have studied and answered the questions correctly to get the passing score. Nothing magical about preparation. Also, examine how you were feeling and thinking about the exam during your prep period. You may also think about whether or not you really want to pursue this career or even whether you have the necessary skill-set and/or aptitude to be successful. So, as you prepare for your next exam, be mindful of how you are feeling as you prepare. Are you excited about the work? Do you find studying challenging and are full of expectation after you master small segments of the overall material? Are you happy to be on this path? Do you look forward to the time when you can study? Hope this is helpful.

Well,I can understand your situation.I am an engineering student from India.I gave an important aptitude examination in 2014.Please be patient to read my following article.I hope positively you will get benefitted from my personal experience.

I too had not prepared well,so to say,at that extent for the exam.I was feeling very depressed,I had only 2 months time for preparation while they say that minimum 6 months is needed to even qualify this tough exam in engineering.Then Someone told me about this affirmations,LOA or whatever you name them.I really studied hard those 2 months sincerely.But never forgot to keep calm and have a positive mentality in every situations.I gave many mock tests and scored well in most of them.Of course before giving the actual exam little doubts,fear hovered in my mind but I never let them to sabotage my positivity.Because I knew little doubt and tension is necessary for every candidate before exam.Finally I gave my long-awaited exam.Some questions ere tough but maximum easy.I never lost my cool.And during each and every moment of my exam(including those mock ones)I thanked God for whatever good and nice he had doen for me.After my exams were over I arranged some dummy results pic from the inetrnet and replaced their names,scores and other credentials with that of mine.I used to regularly visualize them in front of me with happiness and thanked God for the same."Thank you God for everything.I have given my exam so well and my results are very good.Now I can get admitted to those premium colleges or even get a good job.Thank You, Thank you very much."Finally my results came out and I scored 78.66% marks.The qualifying marks were 30 however.Now I have applied for many jobs as well as some good colleges for higher studies.I am waiting for their replies and I hope with his Grace and my affirmations i will succeed.Thank You.