Seek unity. Remember that you have an enemy, and it's not each other. Gaurd your heart. When you are tempted RUN to God and your spouse. Be open, honest and transparent...secrets create footholds for the devil.
Forgiveness doesn't mean it didn't happen, it merely releases you from the pain of having it happen to you. Give your pain to God. He is big enough to take it and loves you enough to hold you while you cry.