You’re absolutely right! You’re having a lucid dream! (A lucid dream is a when we’re awake and alseep—both at the same time.) In your case though, you are feeling the paralysis of your body that occurs each night during REM (dreaming) sleep. And it’s not too comfortable a feeling!
Have you ever thought about why we don’t move around in our sleep, and act out all the dreams we have? It’s a good question, because we all move around a lot in our dreams. We run, we jump, we go swimming, we talk with our friends... Just about everything we do in waking life, we do in dreams. (And then some!)
The reason we don’t act out our dreams (get out of bed and go running around...), is because our bodies are paralysed. We think we’re moving in a dream, but all the commands from our brains actually are intercepted before they can reach our bodies—at a place called the “reticular formation”—at the top of our spinal cords.
In your lucid dream, you’re awake in your head, but your body’s still asleep! This is why you feel like something is “holding you down,” and it’s also why you can’t speak when you try to. Your body is paralyzed! The reason why you sometimes can see blue figures in your room, or hear buzzing sounds, is because you’re drifting back and forth between waking and dreaming.
Everyone gets spooked by “sleep paralysis” dreams. The good news about them is that no one has ever been permanently paralysed, and they usually only last about twenty to thirty seconds. In fact, once you get used to them, they can even be kind of fun. If you can concentrate on having some cool dreams while you’re “half awake” and “half asleep,” you’ll be a full fledged lucid dreamer. Awake—inside a body that’s still sleeping!