For me the key is understanding my circle of influence, it's really very limited as most of us are (unless we're president!)

I do what I can when I can, partly through volunteering and also in how I treat my family and friends, and although it might not seem much it's still a positive effect on those people. We can all make a positive difference in some way.

For the issues you write about maybe investigate what you can do to help influence change. Perhaps you can join a pressure group, and campaign about the issues you feel strongly about?