There are a lot of things to be angry about, and a lot of us that are angry. That anger can be constructive... but is it always? Maybe it's good to remember that the important thing in the work for justice is not the end result, but the love behind it.
What makes you most angry about the world? How do you wish it was different? Who are the people you are most angry at? Why do they believe what they do? What hopes or fears or dreams do you have in common with them in this cause?