We once brought an amazing piece from the Ohr Hachayim on Acharei Mos (in Chizuk e-mails 379, 381 and 385 on this page).
To see the original text of the Ohr Hachayim, please see here
(You can print it out to read at your convenience).
To summarize, the Ohr Hachayim writes that we are unlikely to succeed if we try to fight the Yetzer Hara head-on. The only way to succeed in this struggle is to diligently guard our eyes and our thoughts. However, once we are thinking about these things, and especially if we see the temptations before our eyes, it will often be too late and we won't be able to control ourselves.
And he brings a few examples, that even the greatest Tzadikim who feared Hashem with all their hearts felt powerless when faced head-on with lust. As we see with Masya ben Charash (#46 on this page) and Rav Amram, Rabban Shel Chassidim (#275 on this page). In both these cases, once they were faced head-on with lust, these great Tzadikim had to take extreme measures to ensure they didn't stumble.
What we can learn from this, is that "Fear of Heaven" alone is often not enough to save us from sin once we are face to face with these desires. "Fear of Heaven" can, however, help us take drastic steps to save ourselves, like these great Tzadikim did. When Rav Amram called "Fire!", he was using the immense power of accountability to stop himself. And when Masya Ben Charash burned out his eyes, he was ensuring that he could never again be tested with lust.
In our case, we can at least make sure that we install fool-proof internet filters, and avoid going to places where we know that we will have a hard time guarding our eyes.
We have discussed many times in recent e-mails the idea of "Letting Go and Letting G-d". When we learn to do this properly, Hashem does the fighting for us and we don't have to "overcome" the powerful Yetzer Hara on our own. Our part is just to live with Hashem's help and take the steps we can, to ensure that we do not continue feeding the addiction.
I found a beautiful Pasuk that seems to convey this very idea, i.e. that when we let Hashem do it for us, we have Hashem's strength and not our own! The Pasuk says: "Kovei Hashem - Yachalifu Koach - those who hope to G-d exchange strength", meaning, one literally exchanges his strength with Hashem's.
The Ohr Hachayim that we mentioned above, also describes this miraculous phenomenon. He asks, if someone has already fallen into these things and can't help thinking about them, how can he possibly hold himself back from sinning? So he quotes the Pasuk in Acharei Mos: "Speak to the Children of Israel and tell them, I am Hashem your G-d. Like the ways of the land of Egypt that you have dwelled in their midst, you shall not do". Explains the Ohr Hachayim, that the Pasuk is hinting to us that for someone who "dwelled in the land of Egypt" and has already accustomed himself to seeing and thinking about these things, the Pasuk therefore starts off with the words: "Tell them that I am Hashem your G-d". This is to teach us that, (and I quote here the Ohr Hachayim): "While it is impossible with human strength... with G-dly strength, you shall be able to be victorious over the natural, physical drives".