Marriage/relationship: Forgiveness vs unforgiveness

1 - Unforgiveness doesn't vindicate your pain. If I just hold onto this pain, that will somehow vindicate me. That means you are carrying that pain even longer.
Forgiveness is just as much for your own healing as it is for your partner. Maybe even more so on your part as it heals you.
2 - Forgiveness doesn't mean the relationship is back to normal. Relationship dynamics need to shift and trust needs to be re-built. It is your spouses job to re-build it.