We understand that you're feeling disturbed by a man who is mentally invading your thoughts. Firstly, let's address the spiritual aspect of this situation. The Bible tells us to take every thought captive to obey Christ (2 Corinthians 10:5 WEB). This means that we should not entertain or dwell on thoughts that are not pleasing to God.
However, we must address that the phrase "mentally invading" could be suggesting that there is some form of mystical or psychic connection. We firmly rebuke this idea. Such ideas are not biblical and open the mind to demonic influence. Be sober and self-controlled. Be watchful. Your adversary the devil, walks around like a roaring lion, seeking whom he may devour (1 Peter 5:8 WEB).
Instead, put on the full armor of God, so that you can take your stand against the devil's schemes (Ephesians 6:11 WEB). This includes taking control of your thoughts and submitting them to Christ. There is no power in someone else controlling your thoughts. You are responsible for your thoughts and give the control to either to Satan or God. God can help you guard your heart and mind by hiding His word in your heart, that you might not sin against Him (Psalm 119:11 WEB).
Let's pray together:
Dear Lord Jesus,
We come before You, lifting up this person who is feeling mentally invaded. We pray that You will give them the strength and wisdom to take every thought captive to obey You. Help them to renew their mind according to Your word. We rebuke any evil influence or demonic activity trying to control their mind. We cast out these demons in Jesus name. Help them to understand that only you can have this control. Please guard their heart and mind with Your peace. Guide them into all truth and give them discernment to recognize any ungodly influences. Protect them from any harm and help them to walk in Your light.
In Jesus' name, we pray. Amen.
Remember, God has not given us a spirit of fear, but of power, love, and self-control (2 Timothy 1:7 WEB). Trust in Him, and He will guide you through this situation.
If there is a person who is harassing or bothering you, then you should take steps to remove yourself from their influence. If this person is a boyfriend or just a friend, you should assess whether this relationship is pleasing to God and if you should walk away. Seek godly counsel and ask for support from fellow believers.
Finally, we noticed that your request did not mention Jesus. It is only through Jesus that we have access to God. For there is one God, and one mediator between God and men, the man Christ Jesus (1 Timothy 2:5 WEB). There is also no other way to be saved except by Jesus. Jesus said to him, I am the way, the truth, and the life. No one comes to the Father, except through me. You must believe in the Gospel. The Gospel is the good news that Jesus died for the sins of the world and rose again. By believing in Jesus' sacrifice, we can be saved from our sins and have eternal life (John 3:16 WEB).