Exercise will make you happy, but only while you're doing it. Getting a raise will make you happy, but only for a short time period after that raise. "Having" a relationship won't make you that happy, but the process of building the relationship is highly enjoyable.
The key to happiness is to do those things that make you happy while you do them. Sacrificing your personal now for a better future is one of those church ideals that always struck me as weird. That said, if you work on making the planet better, that work will probably also make you happy as long as you keep doing it. But the "better planet" itself is too abstract to make you happy long-term.