...a reflexive, aversive reaction to ruminating. I'm almost more scared of ruminating, and the places that leads, than I am scared of pain. I don't know if this is a psychologically healthy stance...

I think it is. My own life is pretty good, actually, but I could easily talk myself into a depression if I didn't try and avoid ruminating as much as possible. "Don't believe everything you think"—I learned that here on LW, and that alone is easily worth all the time I've spent on this site.