It wasn't that Jimin didn't like himself, it was just that he wasn't content with himself. He wanted to sing better, dance better, he wanted to look better. Not for himself, but for the fans. He felt too short, too clumsy, he sang too high, and he ate too much. But it was fine, he was fine. 

Hoseok thought otherwise. Their Jimin seemed different, he didn't shine as much as he used to, and he wanted to help. But the other members didn't seem to notice a thing.