My endo prescribed Metformin for me almost a year ago. My A1C was 5.9 in April 2015, down from 6.0 in December 2014. I've noticed that when I miss taking the Metformin pills (I'm forgetful), I sleep better at night, and when I take it as prescribed (2 pills morning & 2 pills night), I wake up around 2am every night, with a sweat soaked pillow. This has been going on for a couple of months now. Recently, I've started waking up with mild headaches. What's going on?