How do you know if you are going into REM sleep. I do not feel like I am, I wake multiple times a night, have trouble falling asleep, I'm tired, weak.

Rem sleep. Rem sleep is a deep level of sleep. It's usually associated with dreams, but if you sleep well you may not remember them. Sound like you may have sleep apnea. If you are overweight lose weight and see your doctor for an evaluation. Sleep apnea can cause serious health issues .