Answer:
You put forth the effort to do something worthwhile. You tried in the best way you knew how. It didn't work out -- so what? Look at what you've gained.
Trying and failing have become two of your most important teachers. They can teach you how to walk the path of success. Failure encourages better thinking. It forces you to look back and ask, why didn't that work?
What went wrong? When you try, you learn. When you fail, you learn even more. Keep trying, and keep failing. You will soon become a very educated student of life.