If you believe that Jesus is Lord, and having accepted Him in your heart, the speaking of tongues is an outward expression of God living in you. However, that doesn't mean that the sinful desires of our past life disappear. In Romans 7:15, Paul says, "I don’t really understand myself, for I want to do what is right, but I don’t do it. Instead, I do what I hate." He is a believer and follower of Christ, and yet he struggles. The bible goes on to mention that the struggles are a result of the sin living in him, as is in all of us. Read the rest in Romans 7:15-25. There are many pieces to understand this and recover from it, but know that deliverance from sin doesn't mean that the temptation goes away. Deliverance means you now have the power through Christ to say no, and walk away from it. You may even feel weak in your own attempts to deal with it, but that is also when God is strongest... In our weakness. Now there is a part that we have to play too. We have to walk very closely with God. That means being very mindful of conversations that we participate in, old friends we hang around, movies we watch and songs we listen to. Consuming the wrong things will feed desires like this that God wants us to walk away from. You are at war in your spirit from the moment you said no to the porn. So to get you to come back, the enemy will tempt you with old desires. You can only win this battle in the spirit, through prayer, worship and sometimes fasting, along with some practical things that we mentioned earlier. You're weak because your own strength won't work for this, you need God's strength. When the desires return, go to prayer. Partner with a friend, mentor, or minister whom you trust, that will pray with you and for you, but will also help you stay accountable during your weak moments. Remember, if you've accepted Jesus, He's living in you. You have the power now to say no. We love you and are praying for you.