Hi. This is something I have seen that everyone goes through. It is difficult for you as you have never seen failure since you were a good student and got great marks. I would suggest you to motivate yourself by reading some self motivating books like (which I personally read and recommend) chicken soup for the soul (there is a series of them and you can pick and choose). Discuss it with your parents or just generally ponder over them. List down your positives and strengths and try not to be too harsh on yourself. Jot them down and focus on them instead of one failure, which is a difficult thing to do but that's exactly what keeps us going. If you are unable to come out of this, see a counselor and he or she will be able to guide you better with more techniques and ways to overcome the same. Hope this helps.

Hii there Success is not rated only by the marks. First mantra of success is being happy. This is just the building blocks. Don't get demotivated by these small setbacks of life. Learn from your mistakes try correct them and get back with a bang. Moreover knowledge without application is waste. Be clear what exactly you want in life.