When asked of older, happy people, how to be happy, they say it is a choice. Your perspective is vital on being happy. Take joy in the important things. Beyond that, you have to invest in you. People tend to do best when creating something, sharing things, helping others, and socializing with other happy people. Do make time for these. Maybe you can incorporate them together.
Many a time happiness comes with just doing things without bothering about outcomes. So all the important things you want to do should help you to create more such situations. Which also means when you do important things, you won't find happiness.
Don't think that everything will be successful. Just accept everything that happens with gratitude. Happiness is not around you, happiness is inside you.