The first thing you can do is to quit trying to excuse what you did and claiming it doesn't mean anything–because it does. Not only have you offended your wife and hurt your marriage, but you have shown that you are in the grip of something you need to be free from.
After all, have you honestly asked yourself why your wife is so upset by this? The reason is obvious: By allowing your mind to feed on pornography, you are saying in effect that she is no longer beautiful to you, and you have a secret yearning for someone else. You also are admitting that your life is centered in yourself and your own desires, instead of putting your wife first and seeking to fulfill her needs.
The Bible is clear: "Put to death, therefore, whatever belongs to your earthly nature: sexual immorality, impurity, lust, evil desires and greed, which is idolatry" (Colossians 3:5). Don't excuse things that dishonor God; don't even allow them to have any place in your life.
This is why your greatest need is to repent of your sins–not just this one, but all of them–and turn your life over to Jesus Christ. God loves you; He loves you so much that He sent His only Son to die for you on the cross. Be honest about your need of Him, and ask Him to come into your life today.