Hiya,
I am 30 years old and about half that time was spent in addiction to p*rn and lustful thoughts. However, the Lord set me free from that four months ago. Now the compulsion is even gone.
Allow me to give you some advice from a man set free....
1) Lay it before Jesus. Look at my discussion handle. We are More Than Conquerors through him. You CANNOT quit by yourself, but only through Jesus.
2) You cannot break bad habits simply by not doing them. You have to replace them with something. Basically, break bad habits with good habits. Conquer evil with good. When you feel lust creeping you can do several things. 1) Close your eyes and just pray. It almost doesn't even matter what you pray..just pray. Offer a praise, cry for help, speak a word of scripture. 2) Pick up your Bible when you feel the "need" coming. It works. I promise. 3) Someone metioned meditation earlier. Good one. Pick a piece of scripture or maybe a hymn or just think about Jesus and meditate on it. Remember, replace bad habits with Godly habits. Soon the everlasting joy from the Godly habits will make you cringe at the thought of the momentary pleasure the bad habits bring.
3) If you are having a problem with the internet use a filter. I recommend
www.wisechoice.net. Its not free...but its the best. The only way to turn it off is to cancel your service...Its a very accountable, christian filter.
4) Find someone you can be accountable to. Someone each week you can meet with and who isn't afraid to ask you the hard questions. Better yet, find two people. And make sure they are men.
5) Pray that the Lord gives you his eyes so you can see the women you lust after are the children he died for. This is my current prayer for myself.