There is help!
You might want to check out the Freedom Begins Here Personal ToolKit. It contains a DVD which explains a lot of what is going on in a person's brain when watching porn and why it is so addictive. It also explains the sexual addiction cycle and steps to break it when a person really wants to get well (as it sounds that you do). The DVD also contains testimonies of freedom that will encourage and give you hope.
Also included is a Devotional Journal designed to help one learn how to guard their hearts and minds and to put steps in place which will aid in the healing process.
I also recommend that you find a mature believer that you can trust and confide in as an accountability partner.
Also, you may need to see a Christian counselor who can help you in this endeavor to gain freedom and a way to handle this temptation and stronghold in a manner that is honoring to God, to your wife, and to yourself.
It takes courage to ask for help. Most men do not have that type of courage because of pride. I am glad that you do have that courage. You are doing the right thing.
Please take the next steps. I pray that you do and that your relationship with God and that your relationship with your wife becomes closer and greater than ever before.
It can happen, if you want to get well enough to take the next steps. And, I believe you do.