I'm going to be frank here. This issue is one that we must learn to face regardless of how embarressing it can be.
It seems that before I came into the Catholic Church that I didn't give much thought to our call to live chaste lives. I pretty much thought that we were in good shape as long as we refrained from having sex before marriage and didn't commit adultery once we were married. And no one every really taught me differently.
It wasn't until I found the fullness of the Catholic Faith that I begin to see things in a much broader since. I guess on some level I had always knew that pornography and masturbation were wrong but never fully understood the implications of these things.
Now, that I have the Church's teachings to guide me I see much more clearly how pornography, impure thoughts at the sight of an attractive woman, maturbation, etc. act to degrade, dehumanize even, others and ourselves.
A reader has suggested this website True Knights as a helpful resource for men struggling with issues of purity and chasity. I haven't had a chance to fully explore the site yet but it does seem like it would offer some help in this area.
This was one of the things that really made me want to avoid going to confession when I first came into the Church. I was too embarressed to talk about it, even through the screen. I got by with saying, "I have been impure" or "I have failed to be chaste". This worked until I recently moved and the priest called me out on it. In a way he forced me to swallow my pride and really tackle the issue before God.
We may be embarressed by our sins against chasity, but we can't hide behind veiled words to save our pride. Because that is where our weakness lies. We have to face the issues head on.