Don’t be fooled by thinking you should be in a constant state of happiness. The idea of being happy is a relatively new concept.
Anciently, (by that I mean Greece and China more than two thousand years ago) happy meant you had been lucky. Good fortune had visited you. It was not something you earned, but something external to you that caused you to be happy.
However, In America, during the formation of the country in the eighteenth century, happiness was a benefit you shared with your fellow citizens by virtue of living in a free and independent nation.
By 1920, the idea of happiness changed yet again. With the advent of the modern age of mass production and industrialization, happiness was equated with material and financial success, along with urbanization.
And since the 1960’s, the definition of happiness took yet another turn. Being happy is now considered something you can control internally, and achieve personally. Which means, there are more numerous ways of of reaching a happy state of mind. ( ref.: Concepts of happiness across time and culture, Jesse Graham, USC, et al)
All of this tells me nobody really knows what happiness is. The word is an illusive term. It’s not a word with one constant definition. It’s a word you can’t count on to be the same from century to century, culture to culture, and situation to situation. For example, people like Victor Frankel ( psychotherapist) and Jean Paul Sartre (philosopher), who were prisoners of war under the Nazis in WW2, claim they found meaning and happiness while imprisoned. Sounds crazy, right? But these guys aren’t the leaders in existentialism for nothing. Their message: what counts is the very moment you live in right now.
My advice: chill out. Easy for me to say? Not often enough.