way i see it, you kinda challenged your subconscious and he/she simply accepted it. you said you basically prepared yourself for any scary stuff like demons from scaring you. and you told yourself that you wont get scared. So maybe your subconscious thought outside of the box and instead of scaring you with obvious things like monsters, it attacked you emotionally on things and topics you're probably sensitive on, like your parents screaming at you, or your mom suspecting that you wanna kill them. or anything emotionally scarring. so in a nutshell, i think your subconscious wanted to prove you wrong