Perhaps you still remember the ache in your heart when you realized that your ex strayed. It's a pain that's often difficult to forget, so one would think that recalling it would cause you to never want to his face again. However, it's also possible that you simply can't get him out of your head, no matter how hard you try.
Belief in Love
People still believe in love and yearn for a special someone to deem them worthy of it, according to Marie Hartwell-Walker, psychologist and marriage and family counselor, in the PsychCentral article “Those Cheating Hearts." If you believed that you and your ex had something special, letting go of that belief can be extremely difficult, even in the face of betrayal. As you sift through the reality of what he did, you may even find yourself still clinging to the image of who you once thought he was. Perhaps you're just missing the man who won your heart in the first place, while trying your best to separate him from the person who hurt you so deeply. Try spending some time with friends and family as you remember what it means to be around people who truly care about you.
Going Through Withdrawal
Love ignites some of the same pathways in the brain as addiction, and losing that love can trigger symptoms of craving and withdrawal, according to research published in the July 2010 issue of the "Journal of Neurophysiology." While you and your boyfriend were at your happiest, your brain and your body were responding physically to your joy. Once is ripped away, it's possible that you are left craving the additional endorphins and excitement your romance was able to provide. If you think this might be the case, consider getting outside and exercising as a natural means of reproducing those endorphins.
Focused on Betrayal
The two fundamental aspects of cheating are the breaking of a contract between two people and the harboring of a secret, according to the PsychCentral article, "Those Cheating Hearts." There's a lot of betrayal which accompanies those two actions, and you may be stuck in a cycle of focusing on that betrayal. As you attempt to understand how your ex could hurt you in such a way, letting go and moving on can feel especially painful. When you feel yourself starting to obsess on the details of his betrayal, work to refocus your thoughts by picking up the phone and calling a friend or turning your attention towards a new hobby or interest.
Give Yourself Time
Feelings of sadness and anger are normal and you should expect them when going through any breakup, perhaps even more so when that breakup was caused by cheating. Allow yourself time to grieve that loss, and surround yourself with friends and family who can support you in healing, suggests HelpGuide.org. Also, don’t be too hard on yourself when you have bad days, remembering that tomorrow is another opportunity to begin moving forward.