Preacher

I am preaching at my church a week from tomorrow and as usual I'm nervous. Its not like I have nothing to say. I just feel completely unworthy to say it most of the time.
Everytime I sit down to study and write out my thoughts, I'm reminded how much of an unfaithful servant and lover of Christ I am.
I know I am called to do this, but I feel so weighted down by my problems and my thoughts and other things. Who am I to be telling others how to run their race with God when I feel like I just stumble at the smallest hurdle? I feel like I identify with the Apostle Paul when we says that he's Paul, called to be an apostle, the least of the brethern.
But I do this because God has called me. I can't deny it. Like Jeremiah said, its like a fire shut up in my bones. Its what I was born to do.
I'm studying about the callings of God, and I'm seeing that we as Christians are not to let circumstances get in the way of fulfilling our ministry. Too many times we can feel we aren't qualified but God has already put his stamp of approval on us.
Right now I certainly feel as though I'm not qualified, but neither did Moses, Gideon, and many other great men.