If a million people, individually, say “there’s not much I can do, my contribution won’t make a difference” then, of course, they’re right. But if a million people say “I’ll do what I can, it may not be much but I’ll do it anyway” then you have a force so powerful that governments and corporations take notice and positive change is possible.
You do not have to save the world, you just have to do your bit knowing that, however insignificant it may seem at the time, you are part of the unfolding perfection of the universe. You have a part to play, and there are no bit parts, so play it joyfully.
That is all.