Recall the greatest times of personal failure in your life.  Were they not times when you were doing what you wanted to do?  And you didn’t feel good about yourself at those times either.  Doing your own thing is fraught with danger.  Proper self-denial is the way to grace and beauty, and to a proper feeling good about yourself.  To deny yourself and resist the forbidden fruit builds character, frees you from gnawing guilt, gives peace, and it pleases God.

“Glory to God in the highest, And on earth peace among men with whom He is pleased.” Luke 2:14 (NASB)