Have you by any chance taken Chantix to try an quit smoking? If so, talk to your doctor asap! And ***IMPORTANT*** get a referral to a psychologist immediately, depending on how long you've been taking it, assuming you have, you'll need to ween down slowly or you'll SNAP and NOT in a good way!
I had a Chantix "snap" 3 months post use, my doctor actually bought me a carton of cigarettes and said the side effects weren't worth it, Chantix kills your pleasure receptors, and causes horrible hallucinations and nightmares.
Just read these;
1. http://nymag.com/news/features/43892/
2. https://www.consumeraffairs.com/rx/
There are so many more, people jumping out of buildings, killing their families thinking it was a dream, etc. I was lucky I recognized the severe attack I was having or I might not be here today.
This is called a Lucid Night terror. Lucid night terrors are merely hallucinations that happen when you wake up from a deep sleep, but you have not regained full consciousness. More people than you'd think suffer from lucid dreaming, and though it can be quite frightening it seems very real. Some people even claim things actually happened when it was merely a lucid dream. Do not worry... Everything is okay! However if they get too bad, I'd talk with a doctor.