Hello,
Sorry to hear your going through this, I’ve been through this myself and I understand how upsetting this is.
From my experience I would say he started using as soon as he came out of rehab, he is probably feeling ashamed and that’s why he’s saying the things he’s saying. My husband(now not together) would go to the meetings and say he was getting clean, he would do a few weeks maybe a month then I would notice a decline, and he would start to say things like we were always different and he was unsure if he ever loved me and even unsure as to why we had kids together. It was heartbreaking and in the end I couldn’t do it anymore. I separated from my husband. He lost everything, he has since been going to the meetings and doing his twelve steps and is 4 months clean. I would mention to your partner about going to the face to face meetings and tell him he can get clean but he has to put the work in. He does love you, it’s just the addiction taking over.