From The Ladder of Divine Ascent by St. John Climacus:

"Do not imagine that you will overwhelm the demon of fornication by entering into an argument with him. Nature is on his side and he has the best of the argument. So the man who decides to struggle against his own flesh and to overcome it by his own efforts is fighting in vain. The truth is that unless the Lord overturns the house of the flesh and builds the house of the soul, the man wishing to overcome it has watched and fasted for nothing. Offer up to the Lord the weakness of your nature. Admit your incapacity and, without your knowing it, you will win for yourself the gift of chastity."

"Our relentless enem, the techer of fornication, whispers that God is lenient and particularly mericfull to this passion, since it is so very natural. Yet if we watch the wiles of the demons we will observe that after we have actually sinned they will affirm that God is a just and inexorable judge. They say that one thing to lead us to sin, another thing to overwhelm us in despair. And if we are sorrowful or inclined to despair, we are slower to sin again, but when the sorrow and the despair have been quenched, the tyranical demon begins to speak to us again of God's mercy."

Having experienced this, I know this to be true. 

"We have to be  especially sober and watchful when we are lying in bed, for that is the time when our mind has to contend with demons outside the body. And if our body is inclined to be sensual then it will easily betray us. So let the remembrance of death and the concise Jesus Prayergo to sleep with you and get up with you, for nothing helps you as these do when you are asleep."

"All demons try to darken our minds so that they may then sugest to us what they want us to do, and so long as the mind stays awake we will not be robbed of our treasure. But the demon of fornication tries harder than all the others. First, by darkening our minds, which guide us, it urges and inclines us in the presense of other people to do things that only the mad would think of. Then whe our minds are cleared we become ashamed of these unholy deeds, words, and gestures, not only before those who saw us but before ourselves, and we are astounded by this earlier blindness of ours. The result is that frequently as a consequence of realizing what happened, men turn away from this particular evil."

While I haven't performed mad acts in the presense of others, I do know that when I come down from the neurochemical high that pornography and self-abuse induce, I usually feel less than human – a disgusting worm or maggot – and I am indeed "astounded by this earlier blindness". If only that were enough to cure me…

"By what rule or manner can I bind this body of mine? By what precedent can I judge him? Before I can bind him he is let loose, before I can condemn him I am reconciled to him, before I can punish him I bow down to him and feel sorry for him. How can I hate him when my nature disposes me to love him? How can I break away from him when I am bound to him forever? How can I escape from him when he is going to rise with me? How can I make him incorrupt when he has received a corruptible nature? How can I argue with him when all the arguments of nature are on his side?"

[…]

"What is this mystery in me? What is the principle of this mixture of body and soul? How can I be my own friend and my own enemy? Speak to me! Speak to me, my yoke-fellow, my nature! I cannot ask anyone else about you. How can I remain uninjured by you? How can I escape the danger of my own nature? I have made a promise to Christ that I will fight you, yet how can I defeat your tyranny? But this I have resolved, namely, that I am going to master you."

"And this is what the flesh might say in reply: 'I will never tell you what you do not already know. I will speak the knowledge we both have. Within me is my begetter, the love fo self. The fire that comes to me from outside is too much pampering and care. The fire within me is past ease and things long done. I conceived and give birth to sins, and theywhen born beget death by despair in their turn. And yet if you have learned the sure and rooted weakness within both you and me, you have manacled my hands. If you starve your longings, you have bound my feet, and they can travel no further. If you have taken up the yoke of obedience, you have cast my yoke aside. If you have taken possession of humility, you have cut off my head.'"