Hey redditors, what was/has been your worst anxiety/panic attack so far and how did you get over it?

One I had some year ago, I didn’t know about that sense of doom you can get, so I sincerely thought I was dying. I was just writhing and shaking and first I thought I had gotten a seizure, then when my left arm started aching and tingling, I thought I was having a heart attack. I called the emergency number, got scolded by a man there for not knowing it was a panic attack, waited it all out, then had a cup of tea.