Please, Go see a doctor. You're going to panic and make it worse until you do.
Until you get there, focus on taking deep, slow breaths and keeping yourself as comfortable as possible.
Unfortunately this is a normal after-effect of a few friends that experienced a panic attack while rolling, or new-timers that were nervous during the whole experience.
But this is your HEART we are talking about. Please book an appointment. Go see a doctor. Let them diagnose you so you can calm down.
Nothing we say here will help you.