Young adult books before I stop being one

As I'm soon turning 18, I want to read the most realistic, gut wrenching books there are in the genre. I'd like to read and relate to different struggles, be it in love, family, and especially of becoming an adult and being scared of your own choices.

EDIT: of course you can read YA books after becoming an adult, and I'm fully intending to do so!! I just wanted some recommendations. I also should have clarified more as a lot of the comments are about sff books, and while I do love those, I'm looking for ya books that are realistic as possible (so contemporary/literary) and tackle life issues.