I am currently on mirtazipine(zispin) 30mg, circadin(melatonin 2mg) and stilnox (ambien) 10mg for sleep. I find since switching from zopiclone to ambien that I am waking 2 hours exactly after I take it. I've read up on it and read that it does only work for 2-3 hours. What should I do? I can go back to sleep when I wake but it takes effort.