In the moments where everything seems wrong you just feel kind of worthless. Like there's no point in you doing anything or being anywhere. And then there's that moment every once in a while, like for me, today, when a random stranger asks you for help and you help them. That's when you realize that even though your contribution to the world may be small, it's still something. Thousands of bees made that jar of honey you have in your pantry. If each single bee gave up cause they thought they're contribution wasn't enough, your pantry would be a little more empty... and there would be a lot of depressed bees.
What you do probably doesn't change the world, but it makes someone's day sweeter. Maybe they need that today.