"It felt like I didn't exist anymore and everything was in a dream."
I've had those feelings before but I think mostly just depersonalization. Not lately, when I was younger. Staying there too long is scary as hell. Edit
@barbaar: For a week? That's horrible!
I had out-of-body experiences a couple times on SNRI's. Very unsettling and disturbing. Sleep hypnogogia (sleep demons) as well. I also had that without any med/substance either. Those dreams stayed in my memory for years Sometimes 2 hours long. Learned how to end them. I couldn't sleep for 2+ days when I got them, absolutely terrifying experience. Feels like I'm being attacks by a shadowy, faceless demon. While in sleep paralysis. Humans evolved not to act out on delusions/hallucinations that occur during sleep -- hence the frightening sensation of being trapped with an entity with no audible scream, no vision on the intruder, and no escape. "Good night everybody, sleep tight!" Just kidding -- .
-I was more concerned about the stimulants.... itching to add them back. For the record various substances worked oddly on SNRI's and better later. And I imagine with PFS too, a lot would work differently. Never tried phenibut or anything like that, probably won't.