Blood pressure meds and hot work environment

I have hypertension and i have tried a few meds to try and control it.
Going to work on my meds seems impossible the heat sweating and my meds combined leads to dehydration i cant not drink enough water thru out the day to keep from having terrible muscle cramps at night when trying to sleep. so i stop taking my meds and i know this is not good but i cant think of anything else. losartan, lisinopril, and Norvasc are the three i have tried but they all seem to have the same results trying to find answers to bring up with my doctor i guess