JPII perfectly describes what it is like when one is attacked by temptations to lust in “Love and Responsibility”. Read on for his insightful analysis and the ultimate solution to overcoming impurity in your life.
 

This gives us a perfect image of those well-known interior crises in which the person undergoes something like an invasion, with its main forces based on sensuality, on carnal concupiscence or (at one remove) on natural sensibility. The person feels the need, natural to a reasonable being, to defend itself against the forces of sensuality and concupiscence, above all because their invasion threatens its natural power of self-determination. The person cannot allow things to ‘happen’ to it which it has not willed. The indirect reason for the person’s natural tendency to defend itself lies in its order of values. Continence is very closely tied up with the natural need of the person to be its own master.

 
Sounds familiar to me. It truly feels like an invasion sometimes when lustful temptations attack. Virtue is the remedy that our Holy Father gives to combat such attacks.
 

Virtue can only come from spiritual strength. This strength derives in the last instance from the reason, which ’sees’ the real truth about the values and puts the value of the person, and love, above the values of sex and above the enjoyment associated with them.

 
You have to educate your mind and feed your soul with the truth of our Catholic faith and what it teaches us about who we are as human beings and learn to see each other person as “another ‘I’”, to be respected and honored as a person made in God’s likeness. With God’s grace, temptations to lust after another person will be mastered using the will by truly understanding who we are as persons.
 
One great starting point for growing in this understanding is the Theology of the Body. There are many ways to begin learning about this wonderful truth, including reading this book, Love and Responsibility, or even the Theology of the Body itself. More accessible ways include reading The Good News About Sex and Marriage by Christopher West or by checking out the Gift Foundation’s website for CDs and other materials.