If you have not checked out the tutorials in DV Wiki, there are some great articles about dream control, content and other useful stuff. I know some dreamers are talking about spinning in the dream to invoke new dreamscape/scenario. Maybe someone here who is more experienced can elaborate on that. Spinning may work for you, if having control in dream is out of the question.
About waking in sleep paralysis - happened to me once or twice. I'm hoping that just reading about it and learning what I'm against will allow me to not be so scared, when it happens next time. Someone also talked about getting out of SP by starting to move your toes or fingers, since small muscles are most likely to get out of paralysis first. Good luck.