Good Guy, Bad Guy

If you've made a commitment to stay with someone who has lied, cheated, or deceived you, you may feel like you're entitled to demand special treatment forever. After all, you're the good person, the one who stayed faithful.
Real healing, however, comes when both parties are willing to examine their behavior and see how they contributed to the situation. Instead of being "the bad person" and "the good person," they work together to build a new and better relationship. You contributed to the situation in some way, even if it was just overlooking "red flags" early in the relationship.
At the same time, remember that neither of you is responsible for the other's feelings or choices. You own your own feelings, and can choose to deal with them in a variety of ways. You own your own choices, including dealing with the consequences. That may mean making changes even if you weren't the one who lied.