She has been staying true to who she is. She's generally always had remorse for killing people. She's felt like complete shit since she must have had the talk with Rick where he told her that the little boy she tried to toughen up with tough love got himself, his brother, and his mother killed on top of Rick's son losing an eye. She feels responsible partly responsible since her cold love turned out to be a total fuck up. Even someone completely disgusting like the Wolf showed to be a human being by sacrificing himself to save the doc, which she didn't think it was possible.
Now she doesn't think like Morgan 2.0, but she certainly sees that there has to be some middle point. And for someone who shows remorse, it also makes sense that that shit builds and wears her down. Some of you just want a super badass. She doesn't need to be female Rick, even though we know Rick is going to dial it back at some point once again since he fluctuates after certain events.. which again is something a human being would do. It's not like she didn't kill anyone. She shot someone in the face who wasn't looking at her once Maggie and her child were in trouble, shoved someone through metal only to have her face eaten while she's alive and burned several people alive. So it's not like she's not doing badass-Coral things, but that all the killing is catching up with her, which doesn't seem unreasonable or unrealistic.
Some of you are just complaining for either things not being spelled out or wanting her to be someone else.
It's more than that, though. It's about her sudden inability to survive and put others at risk, which has NEVER been a part of her character. Anyone with eyes could see that the red haired woman was trying to get close enough to attack her from melee range, and she did just that. Carol should be bitten or killed right now, and Maggie too, for her utter incompetence. That doesn't fit into her character. You can be remorseful and not sacrifice all the survival skills you've built up over the course of six seasons. It's impossible to defend the idea of Carol's complete inability to kill someone to save her own life and Maggie's. I can understand hesitance to murder someone in cold blood (on offence, not defense), but the was NOT the case.
Complete irony in the last sentence of your post.