Cylinder 1 misfire

So,you have had this problem for "Months" and never had it checked out for trouble codes,and have been driving it for months misfiring with the CEL blinking/flashing(and it will shake).You more than likely already have damage to the engine and/or the Catalytic Converters. When that CEL light started blinking it should have been shut off and towed to a repair facility right then! Highly suggest towing to a repair shop now.Damage cost could be a couple thousand dollars,maybe more,depending on the damage.