Most people use nihilism as a justification for their crippling depression.

Nihilism is actually a rather positive thing. It's about "No. There is no 'Great Plan'. You have no purpose. You are not special. You are just another piece of dust in the vast emptiness of space…. so do what you want. Follow your dreams. Don't worry about the universe, see how infinite it is? Why should you give a shit? Don't worry, be happy. If you wanna be special you gotta work for it."

"Existence is suffering"

I said it once, I'll say it again. There's a fine line between nihilism, and being straight out edgy.