When you were young your ego kept you safe. It helped you to become your own person differentiating yourself from others.  It prevented you from making choices that could hurt you.

Your ego helped you to deal with the messiness of life. It was like a parent for you especially if your parents were not present or helpful.   

The inner critic is that part of your ego which exists to keep you under its influence.  As I said above, the ego played an important role in helping you to survive your childhood. You would not have survived without it.

When you grow into adulthood the ego and the inner critic can get in your way if you are not aware of how it is impacting your life.