What he did broke your heart. You must forgive him, as Christ has prescribed. But to forgive him, must he apologize? And if the relationship between you two changes, does that mean you have not forgiven?
Our Lord asks us to love God with all our heart, to love our brothers and sisters, and even our enemies. He also asks us to forgive those who hurt us (Matthew 6.12). Jesus even showed us the example on the cross. “But Jesus was saying, “Father, forgive them; for they do not know what they are doing.” And they cast lots, dividing up His garments among themselves” (Luke 23.34 NASB). To forgive is to renounce revenge. It is to free one’s self from the offense and then be able to be healed. It’s choosing not to bring that back to our memory. After all, that’s what God did when He forgave us our sins. (See this other article on the subject.)
You must forgive, even if the other person has no idea that they have done wrong. Moreover, in their eyes, perhaps their behavior was not bad. But if it hurt you, you must forgive to prevent bitterness to produce poisonous roots in your heart (Hebrews 12.15).
Then comes the second part: reconciliation. Jesus also asked us to be agents of peace. “Blessed are the peacemakers, for they shall be called sons of God” (Matthew 5.9 NASB). If your brother hurt you, you must forgive him and then try to repair your relationship. “Now all these things are from God, who reconciled us to Himself through Christ and gave us the ministry of reconciliation (2 Corinthians 5:18 NASB). God forgave us, but when we repented, we were also reconciled in our relationship with God. Forgiveness is given, even though there is no repentance. But there can be no reconciliation without repentance.
In the same way, we must forgive our brother who has hurt us. But we must also try to reconcile with him by explaining the situation. If he apologizes, there may be a reconciliation between you two. And ideally, we should always reconcile with our brothers and sisters, to keep our spiritual unity.
Then comes the third step: rebuild trust. We must not trust blindly. We must be wise. Trust is a feeling that can take a long time to create. When a conflict occurs, we must forgive, reconcile (if the other party agrees), but it is likely that trust will have to be rebuilt and that can take time.
Now, if you are at the dating stage, and a major conflict breaks out between you two, you can stop your love relationship. Since you are both children of God, you must come to terms, preserving your spiritual brotherly relationship, but you do not need to continue your love story. Dating is precisely a time when you get to know each other, where you build your trust in order to make a commitment for life. If trust is broken even before marriage, you do not have to continue and force yourself into that relationship. Reconciling with each other does not mean you have to continue your relationship. Of course, there will be several small conflicts: you are two imperfect beings. But if the conflict is such that you no longer trust that person, you do not need to continue that relationship.
When you will be married, it will be different. You will have to repair the broken pots and rebuild trust because divorce is not an option. But as long as you are not committed in front of God through the bonds of marriage, you always have the option of putting an end to the relationship. Since you are children of God, if there is to be a break-up, it will always be done with mutual respect. “If possible, so far as it depends on you, be at peace with all men” (Romans 12.18 KJV).