Happiness is built bit by bit on the unknown, by working and sacrificing for something beforehand. From there it flows to the present. Present good deeds and effort, will come back eventually. Karma.
Instant gratification, pleasure does the opposite as it does not require work and effort. It provides the reward first, but the reward is never enough. Rewards get less and less pleasurable. Quality of the pleasure continues to suffer and the attempts to patch that with quantity only make downward spiral worse.
Happiness is the peace of mind that is achieved by doing your best each day. Knowledge that good will come to you, if you do good things.
One way to ensure that you are each day happy from now on is to define the categories and priorities straight and then each day start working from the critical towards the small.