Fadhila,
Porn is a product of Satan. Your request tells me that you realize that watching porn movies is wrong and you need help for that. First of all, you need to pray about it and ask God to intervene, and you must trust Him that He will do it for you. Secondly, you need to follow God's Word to the letter and do what He instructs you to do. That you will find in Exod 20. - The Ten Commandments. Following the Commandments of God must not be a burden to you. I do not say that following the Commandments will save you, but if you love God, the Commandments will be written on your heart and it will become part of you, meaning that you will live out the Commandments like Jesus Christ has shown the people on this earth when He was here. When it comes to the porn, find an excuse not to join your friends watching these movies as that is when it normally happens. If you are on your own, then, when you have the urge to watch a movie, to do something else like, making yourself a cup of coffee and do some Bible study or go and work in the garage or find anything else to keep you busy. God will give you the power to overcome if you try hard enough from your side and also being earnest about it. Porn is evil and from Satan. Many people have the same problem as you have and you are not alone. God is the only one that can save you from this, but it starts with you. Also do not forget, God loves you. You are His child and you need to listen to Him. May God be with you on your path of healing.
