Happiness is an attitude. If you are used to being unhappy, even in the best of situations you will still grumble and be unhappy. Nothing can make you happy in the world.
Being unconditionally happy is a practice. “Come what may today I am going to smile. Everything is going to vanish and disappear, so what? Let me be at least happy. Smile this very moment and enjoy my very breath if not nothing (else)”.