Q&A How Can I Help My Mate Break Their Destructive Cycle?

I love my husband and want to remain together. I had an affair after 30 years of a happy marriage. I blame midlife issues, empty nest, etc on my poor choices. I take full responsibility. I did have some phone contact for an additional 6 weeks after D-Day. That is very hurtful to my husband as he feels I should have been able to never speak to my affair partner again. But that has been 2 years and 9 months ago. No additional contact. Often we are great. For weeks even. But inevitably he gets upset, furious, depressed, and remains that way for 2-3 days. I never know what to expect and worry constantly about when the next bad time will occur. I worry I have hurt him irreparably. Am I wrong to think and hope that we can remain together and live happily? I harbor tremendous guilt already but thinking I am just prolonging his agony makes it worse. I feel I am doing everything right. He says I am. We enjoy each other and have a wonderful family. Why can he not just stop this cycle?