I agree with you that dreams are an unconscious way of talking to oneself, and imo, the brain trying to reason or file ideas and events.

The only person that can interpret a dream fully accurately is the dreamer.
What another might suggest might not be the accurate interpretation, but might cause you to think of what is.

What you watch on tv, in movies or read in books can greatly affect your dreaming if done right before bedtime, or as in this case, is violent enough. Even if you dwell on your previous dreams right before bed, it can cause a link and another similar dream.

The base point for you, if you aren't feeding it negatively as above, is that yes, you are trying to rid your world of something or someone.

Sometimes people try to "kill off" those who help them when what they really want is assistance to die and get out of the life they are in. We see if often with therapists, where the patient not feeling they want to be helped because they are feeling so poorly, try to offend or threaten the T, or put them down and talk bad about them, in an attempt to rid them from their life so they can have a "reason" to end their own life.

Are you sure of your sense that what you are killing off are the good attributes? If so, then go with that. Is there possibly another category that you may have missed?