i've had those exact same symptoms because of a panic attack....it really is as bad as you say....one time my pulse was so fast i could not even count it...i was sure it was the end....but 30 yrs later, here i am!!!

have you ever been diagnosed with panic attacks....they can come out of nowhere and seem like they actually "attack" you without warning or prevocation.
go to your doctor as soon as possible and tell him what happened....i was put on inderal and it almost stopped the attacks in their tracks....it is a tremendous help and i'm still on it to this day. relief is possible..
let me know what you decide to do....i care........................peace:angel: :wave: