I once felt something similar, that my brain was trying to kill me. I "knew" this probably couldn't be, but I felt it so intensely. Every time I've been psychotic some little part of me was saying "now wait a minute". But I still had psychosis, even though I was aware of it. Same thing with mania. Even when I'm manic out of my mind, I know that it isn't my true state of being. Maybe I'm just very self aware. But I think you can have psychosis and at the same time know it's not real.