Our mind is like a computer. The way we program it will determine how it's going to function. Just like a virus can slow down a perfectly good, working computer, our wrong thinking can slow down our destiny. In fact, our lives follow our thoughts. If you're going to live in victory, you have to learn to hit the delete button and silence the negative thoughts. Romans 12:2 says to "Renew your mind with God's Word".
Turn off the negative recording that's reminding you of everything you're not and start reprogramming your mind with God's Word and who He says you are.