I have been using my Res Med CPAP for 2 1/2 years and can't stay asleep for a whole night except for once in a blue moon. My doctor tells me my apnea is controlled while I use the machine, but it doesn't seem to make a difference. Sometimes I can fall back to sleep and sometimes I wake up and can't get back to sleep for a couple of hours. I am so frustrated. I would appreciate some advice.