First, look for cheering up things online! I love positive energizing quotes!
Then there are many different ways to make yourself more confident like mentioned in other comments:
give a look at http://www.wikihow.com/Build-Self-Confidence
there are even more very interesting articles that can help you improving your self confidence a lot by yourself!
If you just can't get it, look for professional help like a coach. They are a good mental assistance! facebook.com/your24hcoach
Best luck with it!