Thanks for providing all the detailed background. As you have observed over the years, this “dream” occurs whether you are in a relationship or not. This is indeed good news, as it lets your current romantic interest off the hook! (He’s not responsible for your bad dreams.)
The event you describe—surprise—is physical in origin, and not psychological. Each night when we enter into REM sleep when dreams occur, our bodies temporarily become paralyzed. The reason for this paralysis during REM is protective. It prevents us from acting out our dreams. Occasionally when we wake up from a dream, though, our bodies can fail to release us from this temporary state of paralysis. When this happens, our mind is awake, but our body still is asleep!
During REM paralysis, we are unable to move, to call for help, or even to take a deep breath of air. The paralysis of our body can be experienced as heaviness and weight. Because our minds still are not fully awake, we also can imagine (dream) that an intruder is in our room, on our bed, or even pressing down upon us, preventing us from getting up and escaping. The confusion and disorientation that results can be terrifying. REM paralysis is one of the most terrifying events that occurs during sleep, but significantly, its occasion does not signify psychological trauma or disturbance. Instead, dreams of attack and intruders are simple representations of our fears of vulnerability.
The voice you hear is explained by the fact that, though you are partially awake, you still are in REM, and drifting in and out of dreams. The sensation of levitation also is explained by the paralysis. In the Middle Ages, your experience was known as “incubus”—a momentary possession by an evil spirit. Today though, we know the culprit is much simpler. REM paralysis typically occurs when our bodies are tired. What’s the solution? Remind yourself that there are no intruders or goblins, and roll over and go back to sleep. Your body is tired, and wants to catch up on its rest.