I've been trying to have a lucid dream for about three months now. So far, the closest I have gotten to is my body having a sensation that I am falling through a black hole (I can sometimes see flashes of light, too). I can hold this feeling for about 5 minutes, but then I always wake up. Also, I've noticed that when I am dreaming I know that I am dreaming, but I can't do anything about it. My dreams seemed almost locked down somehow. Where should I go from here?