How can I gain control of the situation? And, come to think of it, why do I have this problem in the first place?
One of the most important things to know when an improper sight is imposed upon your view is that its grip on you will fade! The sight could trigger an intense reaction in your mind. You might even think, "I can't shake this." Don't allow the force of imagination to rule over you. It is an illusion, a mirage. Remember that your attention to the mental image is the only fuel that keeps it alive. Simply let it pass and it will dissipate and vanish. Like flipping the page of a book, you can switch the focus of your mind. Force your mind to turn that page.
The classic Mussar work , Mesilat Yesharim (Path of the Just) by Rabbi Moshe Chaim Luzzato (Ramchal), tells us that G-d placed us in a physical realm with many things that distract us from coming close to Him. Why would He do that? There are a good many Mussar works that probe that very question, and you may want to look further for a deeper discussion of this topic. The short answer, however, is that G-d put man on this earth as a creature with free choice - bechirah. He wants us to exercise this G-dly trait in order to serve Him with conscious intent, not as robots or angels that must do as they are told. So He gives us choices to make - real choices in the form of challenges.
The very first chapter of Mesilat Yesharim expresses this concept: The purpose of man in this world is to fulfill mitzvot, serve Hashem and withstand tests.
Our mission is to use our power of choice to win the war of kedushah over desire. When you choose to align yourself with kedushah - no matter how many setbacks you've had - you will arrive triumphantly in the World to Come. You will have used your lifetime to come closer to Hashem, the true desire of the soul, and in the process became spiritually fulfilled. In the next world, the dimension after death, that fulfillment takes the form of intense spiritual pleasure, expanding eternally.