Hi, Dalibor.
A good place to start learning about your true identity in Christ would be in Ephesians 1:15-2:7. There, the Apostle Paul prayed for the saints at Ephesus that God would open their eyes to different spiritual truths. One of those truths is that after Jesus was raised from the dead, he ascended back to the Father's right hand in heaven where he is now seated far above all principality, and power, and might, and dominion, or far above all of the demonic forces that we are at war with in this world. Paul also said that when we were quickened or made alive in Christ at the time of our spiritual rebirths or when we were born again, God raised us up together with Christ and seated us in heavenly places with him. This world is currently under the strong influence of Satan, the god of this world, or the prince of the power of the air, but we can overcome all spiritual forces if we get the revelation of who we are in Christ and the authority that we have in him by being seated together with him in heavenly places. I would strongly encourage you to pray the prayer that Paul prayed for the Ephesians for yourself. When you get the revelation of who you are in Christ and how far above all demonic forces you are in him, then the battle becomes much, much easier to win. Actually, I would encourage you to read the entire Epistle to the Ephesians. There is another great prayer that you should pray for yourself in chapter 3, and in chapter 6, we learn about the spiritual armor God has equipped us with to win this battle. If you ever want to discuss the different pieces of spiritual armor, then I would gladly have that conversation with you. It might be best if you more specifically explain your current area of weakness so we can determine which piece of spiritual armor would best serve you to overcome it.
Sorry for such a long response. I will say a prayer for you now myself.