"Don't seek happiness."
- Eckhart Tolle
And don't pretend to be happy when you are not. Very often happiness is a role people play. Underneath the smiling face is a great deal of pain. Depression, outbursts, and overreactions are common when unhappiness is covered up behind a show of gladness. The underlying pain is an energy that eventually must go somewhere. If it is forced into suppression for too long, it will most likely burst out in an inappropriate and over-exaggerated way.
If there is unhappiness in you, first you need to acknowledge that it is there. But don't say, I'm unhappy. Unhappiness has nothing to do with who you are. Instead, say: There is unhappiness in me. Then investigate the source of your unhappiness. It may be related to a situation you are in that can be addressed proactively. Calmly and rationally, reflect on what you can do about your situation. You may not be able to do anything at all, and if that's the case, face what is and say, Right now, this is how it is. I can either accept it, or make myself miserable.
Remember this: The primary cause of unhappiness is never the situation but your thoughts about it.
The situation, any situation, is always neutral. It is what is. Your thoughts, on the other hand, are often filled with inaccurate assessments and reactions.
Be aware of the thoughts you are thinking. Separate them from the facts of the situation. Instead of making up stories, stay with the facts. For example, I am ruined is a story. It limits you and prevents you from taking effective action. I have fifty cents left in my bank account is a fact. Facing facts is always empowering. To a large extent, what you think about what is happening around you creates the emotions that you feel. See the link between your thinking and your emotions.
Rather than being your thoughts and emotions, be the awareness behind them.
Don't seek happiness. If you seek happiness, you won't find it, because seeking an experience will distract you from the experience. It is true that happiness is elusive, but it is also true that freedom from unhappiness is available to you now. You become free from unhappiness by facing the truth of what is rather than making up stories about it.
Within you, at all times, is a vast resource of wellbeing and inner peace. This is the source of true happiness.