Are you f***ing serious?!

So I'm not a closed minded person by any means. I understand that every one has their own views on things and that's awesome! Be unique. I have been in recovery from drugs for 6 years strong now. And because I am still tempted every day to relapse I don't want drugs anywhere near me. My fiancé knows this..and yet tonight I found he has smoked weed twice in the last 6 months. I flipped my shit bc he is also in recovery from cocaine. His big sister died recently from a heroine overdose. So i thought he and i were on the same page about our hate for drugs. Should i call off the wedding and leave him or give him another chance? Please give all the advise possible. Thanks!