Sun was self-loathing and anxious, often putting himself down and doubting himself as he blamed July 16th and multiple other incidents on himself. Sun has had moments of separation anxiety since he and Moon got their bodies. He has also been feeling quite useless and has been hating that and wanting to prove himself as he has a bit of self-hatred, due to him probably blaming himself for past actions and Eclipse's existence. And may even have depression. But, he’s still trying to take care of you