@ Spideyyyyyyyyy Hey, I totally get you. The best site is archive of our own, you can find mostly under the Tag "dark Tony Stark".
I Recommend you to check this ones:
°Fallen Angel By MusicHeart8 (this author as mores Dark irondad stories)
°wrong kind of affection by RevengeWitch
°In the End by Annie_Walker (this one as a sequel)
°I'm going to take care of you now by Hummingbird42 (this author as also plenty of one shots dark irondad related)
°Accidents Bring Us Closer by Us_alive
°The Ties That Bind Us by winterturtle