Fr fr. Like bruh, he still have technically "indirectly killed" Huimin and their unborn child. That obviously left a large dent on his psyche which is why he's understandably acting like this. People in the comments be acting like they're so perfect and morally and emotionally virtuous, when many of them will probably crack harder for less than what the ML has experienced.
Yehh... While i understand where they r coming from, i feel like ml would lose his character depth if he just relaxed and everything is happy-go-lucky becoz final "villain" is dead. The main villain in this book isn't any of the characters. It's the fate that kept pulling them apart. And ml knows this. If i have to say, Hui min, is the less realistic one here. Only becoz of his mental condition, that he can act this carefree.
But i don't actually mind ml like this much. Coz i feel like i would be losing my shit too? If there was a day in my life where me and everyone i love died and even if it's just a dream or hallucinations, i would still be anxious as fck. It's not that i don't trust my significant other, it's just that i won't be able to trust that fate won't say "sike" and fck everything up. So yehhh i feel like ml is being reasonable.