What am I afraid of?

Why do I fear what God wants me to do?

Here Am I, Send Me

Isaiah 6:8

Then I heard the voice of the Lord saying, "Whom shall I send? And who will go for us?" And I said, "Here am I. Send me!".

As far as I can tell, Isaiah didn't hesitate. He didn't wait for somebody else to answer. He recognized that he was there ("Here am I.") and accepted the commission ("Send me."). What more is there to do?