Well, I don't know about that. I think it's possible for someone to behave and treat you so atrociously that they kill your love for them. But that doesn't mean that you never loved them to begin with. It just means they were a real dickhead, and it doesn't make you "bad" for your changed feelings.
It's also okay, though, to keep loving them. Sometimes I think there is a push, when relationships end, to hurry up, get over it, and move on. There is this expectation that "moving on" means that the person with whom you had a relationship should now mean nothing to you, that you'll never think of them, that they are no longer a blip on your radar at all. And that you are weak and wrong if those things aren't true.
It's okay. It's okay to still love them. It's okay to still hope for good things for them. It's okay to be sad that they aren't a part of your life anymore. It's okay that it's all bittersweet.