Joy is what we experience from things, activities, and even adventures. But true happiness comes from relationships.
Joys are passing. That’s why we are constantly seeking new joys.
True happiness, by contrast, is marked by a deep sense of peace or contentment, which in turn is dependent on feeling safely connected to other persons by whom we feel loved and love in return. These other persons may be family, friends or God . . . and to some degree, even pets.
Here’s the proof. A person who has experienced great joys in his collection of mementos, cars, or travels does not receive comfort on his death bed by asking for the things or distractions that gave him joy. He receives comfort by asking for the people in his life who were the source of his true happiness.
Here’s another proof. No one who feels entirely isolated from meaningful relationships is happy. Loneliness is the antithesis of happiness. The lonely may experience joys, but they are not happy. They do not feel socially connected and socially rooted. We are all psychically built to be social creatures. When there is a lack of sufficient social connection we are not fully the social beings we are meant to be and therefore lack a fullness of happiness.
In short, we can only find true happiness in relationships with others. Indeed, it can be argued that the whole purpose and meaning of life is to develop relationships and thereby understand and mirror that Divine relationship which is the very nature of the Trinity. One of the ways we are made in the image and likeness of God is to be in relationship with others like ourselves.
From these insights we can see that key to experiencing and deepening true happiness in our lives is to focus on nurturing our relationships with others, including God, parents, siblings, spouse, children and friends.
Everything you do to nurture and restore relationships (including seeking and offering forgiveness, comfort, and support) will contribute to your happiness and the happiness of others. 
From this same line of reasoning we should also be aware that the temptation to seek individual joys in things and experiences, especially at the expense of our relationships, is like overindulging on sugar at the expense of good vegetables and protein. Whenever our pursuit of joys lead us to neglect our relationships, this will diminish our happiness, not feed it. So be careful of pursuing the excitement of material joys at the expense of your relationships.