Rumination involves negative thought patterns that are immersive or repetitive. Many people slip into rumination when trying to process their emotions, but they become “stuck” in negative patterns of replaying past hurts without moving toward solutions or feelings of resolution.
The American Psychological Association (APA) defines rumination as “obsessional thinking involving excessive, repetitive thoughts or themes that interfere with other forms of mental activity.”
The word rumination actually comes from ruminants - aka cows, animals which chew their cud. 'Chewing the cud' is when a portion of food returns from a ruminant's stomach to the mouth, to be rechewed. Much like we do with our thoughts
There are far better resources from your doctors, therapists, even an online search than i can provide.
However when i do start ruminate, it's nice to have these quotes to read through to distract - and be mindful, atleast your not ruminating!