It's a damn shame they skipped most of the Sheryl & Akira inner monologues, it gave pretty good explanation of why she does things, they also kinda downplayed how MUCH she changed
Yep. In the LN, this is not played comedically. Sheryl straight up breaks. The stress of running the gang + multiple instances of near death (several of those at the hands of Akira) just puts her over the edge and she just shuts down. She only "recovers" by essentially rebuilding herself around Akira, almost as an article of faith. It works, but it's rather horrible.