Help us heal from my sin

Help us heal from my sin: My wife has confessed to me that she feels empty toward me after 18 years of marriage. I broke her heart by going to pornography before and during our marriage and now that I am free of it, she is devastated. We have tried to walk through healing and reconciliation for the last year and a half, but her heart is failing. She says the torment of knowing what I did makes it impossible for her to live with me, and that she longs to be free of our marriage. She won't take steps to finalize it because of our children and the guilt she feels about my heart condition. I had a massive heart attack and triple bypass last year at the age of 39, and she is afraid if she leaves me I will die. So, she is with me out of guilt and obligation, but feels nothing for me.
I am heartbroken, because I feel alive for the first time, and can give her my whole heart, and she doesn't want it.