Below is a daily prayer for the virtue of chastity and the protection of God:

Mary, loving daughter of God the Father, I give my soul to your care. Protect the life of God in my soul. Do not let me lose it by sin. Protect my mind and my will so that all my thoughts and desires will be pleasing to God.
Hail Mary, full of grace; the Lord is with thee. Blessed art thou among women, and blessed is the fruit of thy womb, Jesus. Holy Mary, Mother of God, pray for us sinners now and at the hour of our death. Amen.
Mary, loving Mother of God the Son,
I give my heart to your care. Let me love you with all my heart. Let me always try to love my neighbor. And help me avoid friends who might lead me away from Jesus and into a life of sin.
Hail Mary…
Mary, loving spouse of the Holy Spirit,
I give my body to your care. Let me always remember that my body is a home for the Holy Spirit who dwells in me. Let me never sin against Him by any impure actions, alone or with others, against the virtue of purity.
Hail Mary…