If you are in the area I can take a listen to the motor. You can drive on it with some knock but if you push it hard it will get worse. Plus the longer you drive on it the more damage you will cause. If it is making metal then you may damage your cams and heads from metal in the oil spreading to all parts of the motor. I would say dump your oil and see if you have metal flakes(will look like gold pearl) in it. This will be a sure sign that you have damaged the motor. If no metal noted then add fresh oil and keep an eye on it.

Josh