Contrary to what we might expect, the study found that the link between economic growth, as measured by GDP per capita, and life satisfaction weakened as countries became more affluent. In other words, once a certain economic threshold is reached, additional wealth does not significantly boost happiness.
It is probably the case that, somewhere in the past, you did something that made you more happy/productive/fulfilled, but you don’t do it anymore, for no good reason. Think about that, and do it again, preferably instead of one of your less desirable behaviors.