I think you're looking at girls in extremes; the kind of girl that "[wants] a nice, sensitive guy, who loves them purely, and believes in true love, and does romantic things" is sort of an innocent, naive stereotype, whereas those that like "playahs, party animals, and sex-crazed guys" are really the darker but much more visible minority.
I can't speak for all women but I can speak for myself: I like a nice, sweet guy that is compassionate and can make concessions for my faults but, at the same time, I appreciate if that nice guy has a bit of an ego. Not a mean, egotistical megalomaniac, mind you-- a rightfully earned ego stemming from self-confidence, accomplishment, intelligence, good humor, conviction, and determination.
I like a man that is adventurous, which does not mean nihilistic. My boyfriend does not drink or smoke-- if we go to the hookah bar, he's converse but refrain from the tobacco. If we go to a party, he'll have fun and try a sip of a drink but not down one Bud Light after another. Most of all, he isn't self righteous if I do decide to have a beer or take it hit from the hookah.
Consider these things.
You seem like a really nice guy. Maybe you're just looking in the wrong places for a fitting woman?
As far as that dark, twisted part of yourself that sometimes just wants to be self-destructive? I really, deeply empathize. But it'll pass.