Oh, Writer Lady! You need some cheering up! Let's think of some good that has already happened due to the efforts of people just like you! For instance:
Lead!
There used to be lead in paint and gasoline in the United States. Now there isn't, because people who were concerned about it polluting groundwater and people who were concerned about it damaging the brains of children acted out to fix the situation!
Or! CFC's!
When I was in middle school every can of hairspray in the locker room sent out its own explosion of CFCs. Then, people began educating their peers and their legislators about the effects of CFC on the ozone. Today there are fewer ozone thinners being emitted into the atmosphere, because people cared and acted.
Of course, it's always hard to get enough information in one place to make the "best" decisions, but sometimes trying to make better decisions is a bigger step than it feels like. So keep up the good fight!