Gratitude begets positivity
One of the best ways to be happy is to be grateful. I suggest you start every morning and end every evening reflecting on what you are grateful for. Some days it might only be one thing. Those are the hard days. When you reflect on what you do have and how blessed you feel, it expands. It is just a matter of starting this practice of gratefulness.
This is an on going process. Discipline yourself to start this and I promise you will be happier than you have ever been. Gratitude begets POSITIVITY. All positive thought comes from appreciating what you have, not looking at what you lack.