Was his memory lacking some patches? Did he perhaps in any way forget something important?
"Mu Zhen, I love you...my existence solely depends on you... You are all I want, never leave me alone, alright? Don't leave me even if Zi Xin leaves us... Okay?" She could still confess in that deranged state of hers. This was her regret from her last life and the fears were deeply rooted in her heart.
Mu Zhen had already seen her reaction at the thought of losing him, Wei Tang had cautioned him that her heart was filled will hatred, and all that can wash hatred away was love.
"Okay, I promise you, I won't ever leave you... Now can you calm down..." He hugged her tightly in his arms while he whispered several times across her ears reassuring her from time to time.
After a few minutes, she had calmed down and miraculously the fever subsided and her body temperature went back to normal as she began snoring.