Accused fiancé of lying to me

I felt that he was hiding something and gas lighting me like it happened in my previous relationship so I confronted him calmly but turns out it was a misunderstanding. I was mad that he one person I couldn’t see lying to me might’ve lied so it made me so angry. Turns out he had told me (he says he did and I believe him from the way he says it) and turned cold on me. He says he feels disgusting and how could I not trust him. Even though I felt like my trust has been broken first through misunderstanding but now his trust is broken that I couldn’t trust him if that makes sense. He wants to put it all behind but still says it’s not okay. How do I turn this around?