I've got theories on that post response dynamic. I'm sure you do too. It probably isn't something we could say. There are a few of us here that don't post much about our issues. Maybe people see us differently. Maybe we are different but still.
If you go off I don't think it would mean that person you don't want to be is back. You're under a whole lot of stress. If the way you've become used to dealing with stress isn't getting it done right now then it wouldn't be a big surprise if your mind went back to searching for old ways. And it's an unusual amount of stress.
Bad pain is a huge stressor. A new job situation is a huge stressor. What's going on with Callie... that's something terrible that you just can't fix. That would make for big stress and a whole lot of emotional upheaval. I can really relate to that one. My cat who is senile and whose health is declining. That cat belonged to my mom and he meant the world to her. When he goes it's going to stir up a lot of memories and emotions. Like you and Callie. We can see it coming but there's nothing that can be done about it except wait for it to happen. It's just looming like some big storm waiting to break over us.