I experience these thoughts as well. Mine surface in the form of people dying. I know that it is anxiety as I have had anxiety for most of my adult life.
When I was actively drinking I feared I would do something that would result in my ending up in prison. I do think it is " normal" for the most part. I do think it will go away if you work towards positive thinking, which it sounds like you are. Thoughts are thoughts. They have a life of their own. If the thoughts are starting to rule your life in a negative way please seek out professional help as you are not meant to live in fear and be anxious.