Those are called hypnagogic hallucinations.
Hypnagogic hallucination

I don't know what the significance is when it's also happening in a psychotic disorder but it's not a symptom of a psychotic disorder, only a sleep disorder.
Do your meds cause sleeping problems? Maybe talk to your doc about getting them fixed or maybe have a sleeping aid added? Maybe your current meds are just making your dreams too vivid. When my dreams are too vivid it upsets me as well and it's difficult to shake them out of reality.

When you wake up and think you are awake but then later you really wake up is called a false awakening. I've had those a lot. They are not pleasant.
I've also had hypnagogic hallucinations. I've even woken up with sleep paralysis and had shadow people chanting over me and I even had a disturbing conversation with an Alien once. I've seen floating blobs, random people hovering over me and other disturbing images but the good thing is, they are just dreams and not part of psychosis.
The part of not telling dreams from reality though is scary and I'm not sure what to tell you.
I think you would benefit from learning dream control. It's what I did to control my dreams. I practice lucid dreaming and it's helped with my nightmares so much it's unbelievable.