Disappointment

It sucks when you have such a high hope for something and at the end, it just .... smashed into pieces. I know, people will certainly say that it's silly of me to put such high hope for it. But in reality, you just can't control it. I really didn't put high hopes for it at the every beginning. Then when you are encouraged and praised by your surrounding peers, your self-esteem grows. This is how I started to have faith in myself, or maybe I've overestimated myself. But turn out that I did not get the opportunity that my friends and I looking forward to. Thinking of my disappointed friends and some who may be laughing behind my back, I started to think why do I join it with the qualifications I have? Due to this disappointment, I can tell that I've certainly lost over my self confidence. How can it be rebuild back?