I was 20 years old the first time my implantable cardioverter-defibrillator (ICD) delivered a shock to my heart. It felt like something inside me wound up, up, up and sucker-punched me from the inside out. In the hours following, I had my first panic attack. The air around me got heavy. The weight of it pressed me down into the leather seats of the car as we drove to the hospital, pushing me until I sank away. I rocked back and forth, shook my leg, and scrunched my face to try to stay afloat.