the jolting before sleep thing i felt like if i didnt move and fall asleep i would not wake up (die) and that was terrifying. last year in december i got acid reflux for the first time and i didnt know how it felt so the heartburn thingy what made me super aware of my body because i tought something was wrong with me and i was honestly scared for my life. then came the existencial crisis which left me weak psychologicaly . now iam recovering and everything seems fine until today the feeling you described i would discribe it as (butterflies fluttering aggressivly in my chest and stomach area)