Hi Annie, I was in a similar situation to you. I am with a recovering addict. & on so many occasions he told me that he could beat his addiction on his own and didn’t need help. But after hearing that over and over each time he messed up I realised it was just a way of getting me off his back / a form of denial of how bad his addiction is.
I no longer believed him & kept expressing to him that he needs help & is in denial. He is currently going to therapy. Still a long road ahead but his finally admitted he needs help & is actively trying to get better.