I Can't Do It, God, I Think You've Got the Wrong Person

Ex1-10 Ern's preaching through Exodus on Sunday mornings. Both in his messages, and in my reading, I'm so struck w/ conviction by Moses's response to God's call. I often feel the same about the challenges God places in my life. "I can't do it, God. I want to quit. I give up. Nobody listens. Can't you find somebody else? Is this really where you want me and what you want me to do, anyway?"
I know my attitude makes it all the more challenging yet.
Please, God, help me recognize that I can do whatever you ask of me, because you are at work in me to accomplish your will. You used Pharaoh's dislike of your people to bring glory to yourself. You gave him over to the hardening of his heart and you sent plague after plague to Egypt. How could they deny your existence and your power? How can I?