I expect that we have each of us been betrayed. How do you deal with it? I find in its wake turbulent cross currents of emotion. Almost rich in diversity. Anger, sorrow, self-pity. A revisiting of memories. Perhaps apposite would be a re-membering.
Forgiveness has to be handled with care. In my experience the betrayer most often whips them self into justification and projects back their guilt. The Greek tragedies were full of this. It does make it hard to bear. To have to come to terms both with treachery and the false stories with which the deceiver clothes their actions.
But the most difficult of all? That is in coming to terms with ones own part. If you leave your house door unlocked (as it were), are you not in some measure inviting the thief? Does blind trust not contain elements both of arrogance and lack of care for the relationship?
It takes two both to tango, and to be betrayed. Alas for it, and when it happens. The betrayer in the end loses more than the betrayed; but something valuable leaches out from the humanity of both…