How do I forgive myself

I cheated on my wife and ruined our marriage. She was the love of my life and loved me dearly. We were both in a cult; I "woke up" and she didn't. The only way out of the marriage was to cheat, so as to set her free according to the doctrine of the cult. I didn't want to, but I did it anyway because I couldn't stand being affiliated with the cult. But I still love my wife and now I have to come to terms with the fact that I hurt her deeply because I couldn't endure my situation at the time. How can I live knowing I caused someone, especially someone who loved and cared for me so dearly, so much pain?