Lost Lamb

Today I feel like I have beat my head against a wall again and again and again.  One of my children continues in a behavior that we are at a loss to deal with.   We have punished, rewarded, ignored, cried, screamed and still it hasn't changed.   I feel like a failure, like if I tried hard enough I would be able to change this.  I can't though.  She has to make the decision that she wants to change the behavior.  

I wonder if my Heavenly Father feels this way about me, watching me do the wrong thing again and again and wondering if I will ever get it.  And yet He still loves me.  In the midst of chaos last night I thought of the parable of the lost lamb and how the shepherd left the 99 in the fold and went out to find that lost lamb.  What powerful imagery and what a message.  When the rest of the world would say, "give up and let her go because you have others to worry about", my example is a shepherd who didn't give up on the one.  So what am I to do?