Here are some verses that have helped me...
Why art thou cast down, O my soul? and why art thou disquieted within me? hope in God: for I shall yet praise him, who is the health of my countenance, and my God. (Psalm 43:5 KJV)
"As a mother comforts her child, so will I comfort you; and you will be comforted over Jerusalem." (Isaiah 66:13)
Be anxious for nothing, but in everything by prayer and supplication with thanksgiving let your requests be made known to God. And the peace of God, which surpasses all comprehension, will guard your hearts and your minds in Christ Jesus. (Phillipians 4:6-7)
Weeping may endure for a night, but joy cometh in the morning. (Psalm 30:5)
So do not fear, for I am with you; do not be dismayed, for I am your God. I will strengthen you and help you; I will uphold you with my righteous right hand. (Isaiah 41:10)