Boyfriend Keeps Trying To Detox On His Own

Hello, new to this site. I've been with my boyfriend 9 mo. He lied to me about his heroin addiction till the second month we were together. He says he doesnt want to do it anymore. He went to jail for almost 3 months, said he was going to be clean, and stay clean when he got out, for both of us. He relapsed after 2 weeks. He keeps trying to get off it, detoxing on his own in our bed. He won't go to rehab for many reasons. He goes through the first couple days, then cant handle the pain of withdrawl, so he goes out to get some, so he can do a little bit to maintain, and wean himself off of it. I know that people can wean themselves off of it, but how realistic is this? Am I waiting around for him to get better, while he's just filling it with empty promises? He has lied about using so much, (as most addicts do), that although he is open and honest about it now, that I have lost so much trust in him. I know deep down, he wants to stop, and tries to, but the reality is that he is still using. What is it going to take for him to get better?
I don't have much advice, rehab definitely didn't work for my boyfriend..if anything he fell harder..started slamming heroin 10days after program. He was taking pills prior and never shot anything. I think he had conditioned his brain that pills were horrible but missed the high. Anyway my point is he stayed sober just ten days out, and your boyfriend doesn't want to go for many reasons. That doesn't sound good/serious about wanting to quit. I'm sure you're right that he does, but it's gotta be soooo strong. just wanting to/attempting isn't gonna work you know? Hopefully he will get it sooner then later. As far as tapering question I really don't know, hopefully someone has more knowledge with that. stay strong for you right now, I KNOW how draining it is..