There is a big difference between being 'obsessive' and 'obsessive compulsive'
Being obsessive means you just obsess over something harmless, like a celebrity, or a song, or something. Obsessive-compulsive disorder is much more complex. To put it in the simple terms of the dictionary: Having a tendency to dwell on unwanted thoughts or perform certain repetitious rituals, especially as a defense against anxiety from unconscious conflicts.
So repeating yourself to an EXTREME point, or focusing on something bad and not being able to stop focusing. It can lead to suicidal thoughts.