Practice positive self talk. Make statements like
I know I can do it
I am positive person
I can feel happiness around me
I am going to smile no matter what the situation is, etc
These affirmations will help you realize what it takes to be happy, just one single statement that you need to tell yourself to remind you of your goals and purpose of life. Happiness is all within you, you don't have to look for it outside. Have a happy life. :)