As I'm developing my perception of life.
I thought sharing what I have found in English may be a good idea :
According to a study, People are more likely to suicide when they have meaningless life rather than unhappy life.
So, it may be more interesting to look for meaningful life instead of happy life.
Happiness came after, when you feel the fulfillment of living a meaningful life.
To find a meaning to your life, you must set goals.
Those goals must be coherent with values that you consider as important.
Working hard on goals, doesn't necessarily make feel happy in short term, but at long term it will.
Achieving sub-goals of your main goals every day will cause you brain to release endorphine, which make you fell happy.
So for this reason I believe in this following quote :
“happiness is the progressive realization goals”