On the topic of rumination (as the focused attention on the symptoms of one’s mental distress), Joseph Everett have this interesting article with the gist that “self-reflection is good, but rumination makes you feel worse about yourself”.
And he quotes this interesting observation (by Arthur Schopenhauer):
The best consolation in misfortune or affliction of any kind will be the thought of other people who are in a still worse plight than yourself; and this is a form of consolation open to every one. But what an awful fate this means for mankind as a whole! We are like lambs in a field, disporting themselves under the eye of the butcher, who chooses out first one and then another for his prey.
Arthur Schopenhauer