Join an organization that's doing something to tackle the root of the problem. Socialist Alternative is where I ended up, and I think they're great, but any group that's got a good understanding of the forces shaping the world and has a job for you that you feel is worth doing. Not that that's easy to find through all the noise. I only stumbled across SA because they were speaking at a NoDAPL rally that I happened to go to during a period of relative hopelessness after the election of the orange one.