Hi Ahna,
thank you for your kind and thoughtful responses. I expected all kinds of comments since this is a heated topic. And to be fair, my title is a bit click-baity ;-) Yes, it was over long before the marathon training even. It's a hard thing to hold in my head at the same time that certainly he was shut down emotionally, but also that I chose him as my partner, knowing this about him. I certainly did lots of things wrong in my marriage that I feel terrible for. The reason that I didn't feel bad about the cheating was that he didn't care and didn't love me. As you say, relationships are hard and complex and I just hoped maybe some people will see themselves in my story and ask their own questions.