No Blame Game
Try not to get into blaming each other over whom or what caused the infidelity. It’s just wasted energy. That includes blaming the third party. It won’t change anything. You may have post-traumatic pressure. If you are jumpy, yell at trivial actions, feel like you are walking on egg shells, and continue to have physical reactions when you are reminded of the infidelity, see a physician as soon as you can.
It takes time to get beyond the pain of having a cheating spouse. Don’t expect the mixture of feelings, the sense of confusion and limbo, and the mistrust to go away just because you’ve tried to forgive your spouse and made a commitment to save your marriage.