I think part of being an environmentalist is being a good example for others, but just as being a good example for others means not throwing a plastic container in the trash, it also means not letting the struggles of life eat away at your soul.
Who wants (or should want) to emulate a sad or angry person?
Life on this planet is not all peaches and cream, as they say, and it never has been.
But the way forward is probably not by thinking it should be but by making every experience or challenge you can a learning lesson, by making every step you can a step in a positive direction towards a positive goal using positive means.
You attract more people to your cause with a smile than with a frown or a wagging finger.
Not that this is always easy, but I think it’s an important thing to remember.