It's not that unrealistic. People having mental breakdowns act "irrationally", but there is an underlying logic to the way emotions work. Having been in and also witnessed people being under extreme stress, I don't think this is a bad depiction.
This is fiction, so the narrative is more neat and tidy than in real life.
I'm not really a fan of the comic so far. Usually I enjoy atmospheric padding more but it's falling a little flat for me.