I really feel for you in this situation, it's a hard call to make when you are in love with someone..
Having had a sober cop myself (my ex) I can tell you it doesn't work. I ended up resenting my partner and would drink when we were away from each other. We drank every now and then but under his terms and it was horrible..
I suggest letting him go to find his own sobriety rather than breath testing him everyday. the dynamics of the relationship can change drastically if one becomes almost like a gate keeper..
Good luck with whatever you choose to do..