There's a possibility that your latest hallucination was actually a night terror, and not psychosis. One of the signs of night terrors is feeling unable to move, and you can feel like you've woken up but still be hallucinating (dreaming) pretty strongly, and these are things that non-psychotic people experience sometimes. If you're interested, check out Oliver Sacks' latest book called Hallucinations. He goes through a number of different causes of hallucinations that aren't psychosis or schizophrenia, and it illustrates how common hallucinations are in mentally healthy people (there's a section about musical hallucinations, actually, as well as a section on night terrors and other sleep related hallucinations).
For BeeKeeper: You should talk to your psychiatrist, since it sounds like pre-existing hallucinations are getting worse. And they're distressing you, which isn't good.
I have always had "shadow" people around...but that has been more under control the last couple of years with med changes. Once woke to a small boy standing by the bed watching me. When I finally got the nerve to reach to him he smiled a small smile and faded.
I've never had a hallucination speak to me. I can see where that would have been very terrifying. I'll just hope this new change does not go that far.
I've had changes in my hallucinations. They started out as mere indistinct whispering. Then, they got a little louder, little louder, little louder. I'd see a person in a corner for a brief second, like a ghost. Not long enough to catch any features.
The last hallucination I had greatly differed from this. I was in my parents' room since I'd been seeing shadows in my room and my dad wasn't home, so I stayed in my mom's room with her as being around people generally makes them go away. I woke up and she was already at work, but I couldn't move. There was something off, and try though I might, moving wasn't happening. Finally, my parents' double doors to their room seemed to grow to twice their height and close. I saw the top of a really tall wolf's back at the footboard of my parents' bed. It was walking around to the side I was on. Still couldn't move. Finally, it got near, and I heard a voice, distinct and clear as could be, say: "There are wolves that live in this house." It was beyond frightening.
I would mention this change to your psychiatrist as you may need a medication adjustment whether it be dosage increases/decreases, getting off a med, adding a med, or whatever.