Repeat after me:
The dark side does not bring justice, it does not bring fulfillment, it does not bring happiness, it does not bring love.
It takes, it takes, it takes and it takes.
And all that gives back is pain and anger, suffering and despair.
Nothing good comes from dwelling with the dark side, and when you start using it, you'll fall into the illusion that the power you're receiving will make you achieve everything you ever wanted, but just like a drug, it's feeding you sweet lies to keep you distracted by the way it's destroying both your body and your mind.
There is no peace within the dark side, it is a bottomless abyss, where all you can do is fall, and fall, and fall, more and more to your pathetic end.