There is something about hating yourself that makes one get really self-focused. And, when things are going bad, and you're really hating yourself, and dwelling on yourself, you're also not in a great position to really care about other people, it's more like you want to be rescued by other people. (And I don't mean you you, I mean hypothetically, or me even). It's not selfish in the sense of intentionally being greedy or anything, but it is still a selfishness. When you are really depressed you're not in a good place to show love also, you're not thinking about the other person and their needs, more like your miserable and depressed seeking relief.