Also, look for clues to indicate what might be going on inside. Talk to his teachers or people who see him everyday and see if they notice anything in particular or have advice. Ask him if he's comfortable with how he feels and behaves. If he's not, offer your help in any way that feels comfortable. Often I can hear the voice of a little child in me that needs her for protection.
Any ideas are welcome.
The fact that you notice that this bond is somehow impeding your independent thinking is a major step in the right direction. You should understand that becoming independent and making decisions on your own does not lesson your love or bond with your mother. But that is hard to find out until you try it. Interpersonal therapy is a form of therapy that can help you look at how you interact with others and help focus you on changing that behavior. It's likely you've become reliant on authority figures in general and need to change that.