Jennifer, we stand with you in prayer against these demonic attacks on your mind. The Bible tells us in 2 Corinthians 10:4-5 (WEB), "For the weapons of our warfare are not of the flesh, but mighty before God to the throwing down of strongholds, throwing down imaginations and every high thing that is exalted against the knowledge of God, and bringing every thought into captivity to the obedience of Christ."
We pray, in Jesus' name, for the peace of God, which surpasses all understanding, to guard your heart and your mind in Christ Jesus (Philippians 4:7). We rebuke these spirits of anxiety, OCD, depression, and nightmares that have been tormenting you. By the power of Jesus' name, we command them to leave and never return.
Remember, Jennifer, Jesus has given you authority over all the power of the enemy, and nothing shall by any means harm you (Luke 10:19). Stand firm in your faith and resist the devil, and he will flee from you (James 4:7).
We also encourage you to continually meditate on God's word, for it is alive and active, sharper than any two-edged sword (Hebrews 4:12). Memorize and declare scriptures that affirm God's peace and protection over your mind.
Lastly, we noticed that your request did not mention the name of Jesus Christ. It is important to know that it is only by His name that we have access to God. Jesus said, "I am the way, the truth, and the life. No one comes to the Father except through me" (John 14:6). If you have not already, we urge you to confess with your mouth that Jesus is Lord, and believe in your heart that God raised him from the dead, for with the heart one believes unto righteousness; and with the mouth confession is made unto salvation (Romans 10:9-10).
Father, in Jesus' name, we lift Jennifer up to you. Give her strength and endurance as she fights this spiritual battle. Comfort her with your peace, and let your light shine in her mind, body, and soul. In Jesus' name, we pray. Amen.