Rumination is a process of continuous thinking that pulls one thought after another. The brain draws in our imagination some terrible situations and we cannot stop thinking about it. Psychologists claim that rumination may cause anxiety disorders and phobias. To prevent this you should learn to control your thoughts. If you notice that some particular thought drives you on — shake it off. It is important to consciously catch that idea and stop thinking about it. You can practice mindfulness, or just get switched to something: washing dishes, sports, or playing with children.
This is not a reality. It's just your imagination.
Remember that your thoughts exist inside your head only. We are all afraid of something. Does it mean it will necessarily happen if we think about it? Of course, not. Thought provides anxiety because we willingly pay attention to it. We believe that thoughts are material, but this is not true. Have you noted that as soon as you focus on an actor, you immediately notice his interviews everywhere, his photos on billboards etc.? That is not some kind of supernatural or something, everything is much simpler than it may seem. This happens because our subconscious is looking for confirmation to our thoughts. Think positive and you will notice positive things around you more often.
Is the threat real?
Whenever you worry about your children (or anything else), ask yourself if the threat that bothers you is real.
Am I late? Is this meeting so important to me? Am I really in a bad relationship with my child, or are we both just tired and can't find common ground because of that? Do my kids have problems at school, or did they just fail to prepare their homework yesterday?