Books about terrible people who are trying to be less terrible?

Sometimes it feels like there's something terrible that's wrong with you, like no matter how hard you try to be a good person you'll always have that one horrible piece of yourself that could destroy it all. I'm looking for books where the main plot is about characters who feel like they're bad people, and are trying to get better. Characters who are mean to their loved ones, who keep self sabotaging and burning bridges, who make all the wrong choices while being aware that they are wrong choices.

I'm specifically looking for fiction. I tend to enjoy literary fiction, and I've been liking short stories lately too. I'm not a fan of horror because I'm a big weenie about things like that, so if you're going to suggest something in that genre please keep that in mind. Other than that, open to any and all suggestions! Thanks!