One of the keys to happiness is success. That is why it is important for you to achieve your goals in order to become happier. This could be work related or something from your personal life, whatever it is, work hard at it. Do not let any setbacks stop you from achieving your goal.
Find the best part of you and build on your character from there. Once you take the time to step back and learn the things that you like about yourself, you will be able to build on those things and become the great person that you wish you could be.