venting.. need help

So I've been dating my boyfriend for 4 years, and about two years ago he started smoking weed because he went to college & got into the wrong crowd... so I tried to accept it & smoke with him but he got obsessive with it & did it every day 5 times+ a day. well he got a new job that requires random drug testing so with that being said he quit & was 6 months clean, I made sure I told him how proud I was of him etc, but a few days ago I found pictures in his phone of blunts he was flaunting and smoking, and made plans to do it again the next day if I wasn't available because of work.. I feel betrayed as his SO.. is it wrong of me to feel betrayed? i come from a drug addictive family and he knows that... I love him so much and I don't want him smoking weed ruining it? I can't stand that he still smokes? I don't know what to do :( help