A soliloquy.
The most important decision you can make right now is to build your prayer life. By building your prayer life, you are demonstrating that you want to respond to the conversation that he initiated. Such a decision is important, particularly if you want to recover from a wound caused by a betrayal.
Remember that an act of betrayal is not directed at you in the first place. No woman can betray you without first betraying herself and her relationship with him, and that's the worst kind of betrayal—not being true before him and not being true to herself. Such a life is a lie.
The most important lesson you can learn when someone betrays you is to ask the question:
In what way is the act of betrayal also true to me when it comes to my relationship with him?
Most likely, the betrayal you experienced is just a concrete demonstration of the pain he had when you betrayed him. You betrayed him when you chose her to replace him in your life. You chose her to serve yourself, the kind of life where the center of the world is self. Your greatest idol is yourself, and that kind of life will inevitably lead to chaos and destruction.
In building your prayer life to recover from such pain, the best starting point is to read the book of Psalms. Remember the prophet Samuel. In his eyes, failing to pray for the people of God is a sin. If you are no longer praying for them, you are living in sin. How can you expect his blessing if you are living in sin?
Moreover, by failing to pray, you are not only harming yourself but also his people and the people you love. The greatest blessing you can give to your loved ones can only come from him, and this is done through prayer.