So I read your post and seen as you suggested future diary cuz as you said it's very special i thought it might be good......I just finished the entire anime.....i feel empty inside Never has an anime built me up too such a bitter ending! I love you and hate you for what you've done!
Are you asking for anime detailing sex or violence? If your asking about gore and such there are a plethora of anime titles that match that such as Hellsing, Akame game kill, Ellen Lied, Future Diary. But, if you asking about hentai then I would suggest Lady Innocent, Bible black, etc. Good luck on your search.
I don't think I'll ever understand the "shipping" phenomenon. Then again I didn't get pet rocks or pokemon go either. As long as you're having fun it's all good.