This Man Left Me Clueless

I wanted my marriage to last. I didn't want to give up. How could I give up a man who had been so kind to me for a very long time? What changed in his temperment, to start showing me his bad side? Perhaps it's because he brought an "outsider" into our marriage. He didn't have any right to do this to me. I didn't do it to him, so why did he see fit to think it was okay? I didn't want to acknowledge that my husband, the man whom I loved so dearly could ever think of hurting me this way. I must have been in a "zombie" state to have let it continue on and not do more about it. Yes, I argued with him, but this was obviously not enough. What else could I have done, without walking out? I was just clueless about the whole situation. I didn't want to face the truth.