To put it simply...... place yourself intentionally away from distraction and other people. Find a place where you can be truly alone with God to practice this. During your time of solitude you may want to read the following verses about Identity. read them slowly. intentionally not letting your mind wander.
John 1:12... I am God's child.
Romans 5:1......I am justified.
Romans 8:1.... I am free.
Colossians 2:13..... I am alive.
Romans 8:38-39...... We are one.
Spend several minutes absorbing the truth of your Identity and allow the freedom of that truth sink in. YOU ARE WHO HE SAYS YOU ARE AND NOTHING CAN CHANGE THAT. you do have to choose to believe and claim that freedom though.