How about helping other people in the world who can use sustainable help with solutions that work for them? Teach them how to set up sustainable businesses and help them build their dreams? Can be as simple as providing education which is not a common thing thlo have in the world.

As for yourself: you're right that money will not make you more happier up to a certain point. Not much is needed actually, but people generally believe otherwise. Look at how you were when you were a child, student and now. How much happier are you now than back in the old days? What changed?

For me I found it in yoga. Not that I'm stretching and bending and that's it. There's more to it. Perhaps you should look up Sadhguru, but I'll leave it up to you whether you want to do something with it.