My partner of 2 years cheated on me with his ex.. who has no idea we were even together.

My partner of 2 years who is fa.. and shuts down after any argument/disagreement.. 6 weeks ago he was in the process of moving in. We had a disagreement and he went home. Where he refused to work things out and blamed me for everything. It was totally fixable but in his rage he rewrites the story and things are put on me. During the time he was back home he was very mean towards my attempts at repair and blocked me for a week.. then a week later blocked me again. We started talking again last week. I came to his house and we slept together. I had the worst anxiety while I was there because I could feel another woman's energy.. the house was cleaned. He'd been looking after his appearance.. both are things he doesnt usually do. All traces of me ever being there were gone.. I knew hed been with his ex. This happened 2 months into our relationship when he left me the first time. I questioned him for days and he denied everything.. then finally he admitted to sleeping with his ex, but claims he is done and blocked her. For context she has no idea i exist. He never added he was in a relationship on socials. I was never allowed to tag him in anything. I feel like he kept me hidden from her. So he could go back. Im sick with anxiety. Although hes said he will do whatever it takes to not lose me. He doesnt seem particularly sorry. I dont know what to do. Ive stated my conditions. My biggest one is him telling her the truth . Because she deserves to know too, but he flat out refuses. Any advice would be amazing. Im conflicted. Ive loved him more than anything. And I dont want to not be with him. But I feel so helpless.