Wait..... Why are YOU cutting his meds back??? Are you suddenly a Pdoc? If his meds are not working then HE needs professional help , a Pdoc .. You can mess with your meds all your want and you do ,, But to decide to cut his? Nope ! He needs to listen to his Pdoc and reach out to he/she for help if he feels meds are not working.

I fully agree with Blue.. stop, walk away , go wait 5-10 mins in the bathroom , count to 1215 if need be until you can calm down and have a discussion with him.... Id start with ,, Hey Im sorry things got heated can we discuss the X problem?