"Slowly, I told myself that evolution failed itself by giving a bit more individual selfishness over community/species survival."

There are a lot of great answers here already, but I would like to put forth the anticapitalist position that the quote above is likely false. Humans can work together, we have developed systems of cooperation that can deter selfishness from destroying a community. This is possible (and despite decades of propaghanda..popular!) What is stopping it is the greed for wealth and power of the 1% at the expense of everyone else and the planet. The masses of people are constantly trying to stop this, and mostly fail. But cracks in their power do open occasionally, and you just have to do what you can until a Crack is available for you to help widen. I think it's possible to win, but not through personal lifestyle changes and voting alone. Only through activism and protest is it possible. Most humans keep trying to solve this, and that gives me hope.