Laid down for bed. Then sudden extreme pain run down my back and chest. Fekt like redhot iron, knife stab sensation. Afraid to move. Did I have ♥ attack?

Better safe. For severe persistent pain you have to go to the emergency room to make sure that you are not having a heart attack, a blood clot in the lung or tearing of your aorta. If it was a momentary shooting pain it could be a pinched nerve in the neck.
No way to know. No way to know; see a doctor as soon as possible to find out.