Yeah, the Sicilian is tough. I never liked it myself.
White isn't better, but if you don't know enough theory (and/or the common attacking ideas) then you're pretty screwed.
What are some passive lines to play, should my opponent go for the open variation?
Well, passive is bad, but for example the Sveshnikov is pretty chill. More positional ideas than caveman attacks.
Every single time I play the Sicilian with black and opposite side castling occurs, my black king always get annihilated with some attack. I feel that the white pieces in the Sicilian are better positioned in a way to attack. Is this true or I am just bad? What are some passive lines to play, should my opponent go for the open variation?