Hi, I'd like to help you with your question.
Most people experience thoughts about hurting someone, even their children, from time to time. But when your thoughts begin to interfere with your life and cause you distress, you may be experiencing an emotional disorder.
Thoughts of this nature are usually attributed to many different disorders, but the most common is called Obsessive Compulsive Disorder (OCD). This is when disturbing and unwelcome thoughts begin to bother you to the point you become obsessed by them. You can also experience these feelings in association with Post Traumatic disorder or an anxiety disorder.
Your mind has many ways of coping with distressing feelings. One way to prevent you from feeling something distressing is to create a loop of thoughts that prevents you from facing the traumatic feelings. These thoughts are usually of something that has the ability to catch your attention and can become so intrusive that they not only prevent you from thinking or feeling anything else, they become distressing themselves.
People who actually follow through with hurting others are rarely distressed by their thoughts. They make a plan and follow it through and do not reach out for help. They do not worry about how they feel nor do they normally feel there is anything wrong with them. This does not sound like how you feel.
The thoughts you are having are common with anxiety based disorders such as OCD and PTSD. The first step in coping with how you feel is to find out what disorder you do have. To do this, you need to first see your doctor to rule out any possible physical cause to your symptom. Then once you are cleared physically, ask your doctor about a referral to see a therapist. A therapist can do a full evaluation of your situation and determine a diagnosis. Once you have a diagnosis, it will be easier to determine what type of treatment would best help you. Here is a link to help you find a therapist if your doctor cannot help you: http://therapists.psychologytoday.com/rms/.
Here are some resources to help you narrow down your symptoms:
Once you receive a diagnosis and treatment, these thoughts should go away.
I hope this has helped you,