Scary At First!!

i just remember a couple of years ago, i was asleep in bed at night, and i had this dream/nightmare, and it was as if i woke up, but i couldnt move at all, i couldnt open my eyes or nothing, and then i felt, it was like someones hands moving up and down the front of my body, up and down my chest and stomach, and then i heard the voice of an old man shout in my right ear "can you feel me?" "can you f**king feel me?", all this while i could still feel someones hands rubbing up and down my chest and stomach, and then a couple of minutes later i was finally able to move, and i shot straight up and switched my bedroom light on, and i was like " what the **** was that?" and my whole body was covered in sweat!! since then, i have had a couple of similar experiences like this, when im sleeping,but without the old mans voice i heard the first time and every time, it scares me!!!