Many happy countries have unusually high rates of suicide. … U.S. states … with people who are generally more satisfied with their lives tended to have higher suicide rates than those with lower average levels of life satisfaction. … Adjusting for clear population differences between the states including age, gender, race, education, income, marital status and employment status … still produced a very strong correlation. …

“Discontented people in a happy place may feel particularly harshly treated by life.” … “This result is consistent with other research that shows that people judge their well-being in comparison to others around them.” (more)

While it is good to be happy, be aware that your happiness comes a cost: it makes those around you feel worse by comparison. So please, only act happy if you actually are happy. It is hard to see how your gains from pretending to be happy could outweigh its harm on others. Yes, maybe pretending to be happy makes you a little bit more happy.  But, really, it is ok and probably best to act unhappy if that is how you feel.