Jesus not only told Peter to forgive 70 x 7, but also implied that we would need to forgive more (Mt 18:22). Usually we don't get hurt 70 x 7 because we don't let others have that many shots at us. After a few hurts, we, like turtles, put our heads back in our shells to prevent any additional wounding.
When Jesus calls us to forgive 70 x 7, He calls us to expose ourselves to repeated hurts. "When a person strikes you on the right cheek, turn and offer him the other" (Mt 5:39). He is not calling us to be masochistic, just to love as He loves, to love even enemies. God was and is hurt and insulted 70 x 7 x 70 x 7 times.
If we were God, we would just withdraw from the ungrateful rebellion of our planet and leave it doomed. Yet God does just the opposite. After His covenant is spurned and His prophets murdered, He sends His Son to save us and thereby exposes Himself to even greater hurt and insult (Mt 21:33-39).
By God's grace, let's forgive one another, not only to stop hurt but to absorb future hurts. Some forgivenesses prepare us to be hurt again and forgive again. The hurts go on and we forgive them as fast as they come. The exact translation of Jesus' words on the cross is, "Jesus kept saying: 'Father, forgive them' " (Lk 23:34).