Whenever I feel dissapointed with myself, I always recall this story:
Once there was a boy named Jamie, he was a regular schoolkid. One day, in an annual function in his school.. he wanted to participate in a play really bad. He practiced hard for his roles and had his whole heart into it. However, his mother knew that he won't get selected. The auditions were held and results announced. Little Jamie all excited rushed up to his mother and told her " Mommy, I have been selected for sitting in the audience and clap and cheer for them!".
This short story has given me a lesson for a lifetime. Although, Jamie did really wanted to act in the play, not being selected didn't made him lose his confidence. He was still positive, happy and satisfied with what all he got.
Sometimes, things don't go the way we plan them. Sometimes things don't go our way, whenever this happens, say this to yourself- "Things would get better, I would make them better." Boost up your self confidence, smile and then see the positivity around you.
So believe in yourself, take your own responsiblity and being all positive bring out the change you want to see!