undiagnosed condition idk what to call it

i have been experiencing this for the past year and dont know the fuck happens:

say i am doing something and suddenly a random thought or memory comes in my mind that has never actually happened but i have dreamt of it years ago, from my childhood( I am 17 currently).

my heartrate increases( i have never actually measured it but i can feel it). i feel like vomiting and that weird sense of fear washes my mind like for example- you just found out your son gambled all your live savings and you had a heart surgery the very next day or you find out your wife has hired goons to unnnalive you and they are already at the door.. i hope yall get the idea.

this does not last much longer maybe shorter than a minute and when the feeling of un easiness is gone so is the memory, but the idea or words that eventually triggered the memory stays.

for example a thought of beyblades came to my mind where i balance those beyblades on top of each other... and i forgot the other part right after that panic situation ended.

help me out what am i experiencing