Breaking physical habits will help you to improve your confidence and help you feel better abut yourself. Why? Think about it. If you want change, or want to feel more confident, for example, and never change how you behave and operate in life... nothing is going to change.
To change something in your life - changing a physical habit is an excellent start.
Here is a great practise to change your physical habits: Put a song on and dance and move, paying attention to your movements tendencies. What kind of patterns occur?
Play the song again and then dance to the music, not in rhythm. Observe your movements. Do any new movements occur?
See what physical habits you have in your everyday life. Do something a bit different.