Cast your burden on the Lord, and he will sustain you; he will never permit the righteous to be moved. (Psalm 55:22, ESV)
What concerns are you carrying? Are you worried about the next mission? How about what your family is going through back home? And what about issues with your chain of command? The bottom line is, no matter what is troubling you, the Lord says to bring them to Him so he can help you deal with them. He will keep you and carry you through any and every difficulty. How about having a serious chat with the Lord about your cares?
Prayer: Lord, it is by Your grace that I can bear any hurdle set before me.