Forgive then leave the relationship. I am sure its hard to build the trust and will be walking on eggshells later on.

You have to forgive the person. The forgiveness can come instant or later on. But staying in the relationship is fool hardy. The hurt will always be there, regardless if you have a new gf or partner.

Forgiving is making a mental stand to say this will have minimum impact to your life. If you dont forgive, it will manifest to hate then other issues. Forgive her, forgive yourself, leave the relationship and give space to heal.

Everyone heals differently but will heal in the end. Forgiveness is the first step.

Typical human behaviour, when people hurt you, you wanna hurt back. Sometimes to extremes. And sometimes with regrettable actions. Im sure you dont want that.