Many of us have heard the phrase "Smile and things will get better." The psychological truth is that this is true. If you wake up feeling rotten, hating the world, put a smile on your face and some bounce in your step and pretty soon, you will start feeling better. Most people know that our body language tells a lot about our mood. What most people don't know is that, because of this relationship, you can use your body language to change your mood and how you feel about yourself. If you start acting confident (stand straight, head high, shoulders back, a smile on your face and walk crisply) even though you feel discouraged, your discouragement will begin to disolve. You will begin to feel more confident and sure of yourself. As this begins to happen, you will become more energized and motivated which, in turn, will make you feel even better about yourself.
In the beginning, you will be aware that you are just "faking it". With practice, it will become more natural and will become a genuine part of your personality. You can now start to transform your personality so you will be the type of person you want to be. It will take time and persistence but it does work.