I don’t think its a stretch. What your describing sounds a lot like repression which for sure trigger anxiety attacks. Not surprising a some part of you knows whey a larger part of you does not want to know – blocking flow – experienced heart palpitations and all the stuff assoicated with that.

My untrained guess is that the unconscious issue that you would prefer not to make conscious is something to do with the notion of death.  If so facing your fear and concept of death,  making that conscious should help reduce the number and or  intensity of future anxiety attacks.