Dating a recovering addict

I have been dating my boyfriend for about 10 months and we live together. I knew he was in recovery for heroin and pain pills when we met. He was completely sober when we started dating but slowly started smoking weed and drinking. I don’t have a problem with that. But he confessed to me about 2 weeks ago that he had been taking pain pills for recurring neck pain. I was upset because I felt like he was doing it behind my back and because he obviously has a problem with addiction. We talked about it and he agreed not to do it again. Today, he told me he did it again. I love this man and he is a great person but I’m not prepared to be in a relationship with someone who I can’t control their addictions and will lie to me about it. He has again promised me that it won’t happen again but I have a hard time believing him. Just looking for any helpful advice on how to proceed because I just don’t know what to do.