There is nothing actually wrong, it is just that you have learned to give yourself pleasure by one method and not the other. You are right that learning with care and patience to bring yourself to orgasm using your hand is the corresct next step. There are orgasm triggers in the tip of the penis, so don't be downhearted if it takes some time and practice. Be patient with yourself, though, and read The New Male Sexuality by Bernie Zilbergeld, to make sure you get the conditions right for you to start to work on this.