My heat pump fan blade sounds like it is hitting chunks of ice and makes a loud noise every 30-60 seconds. There is ice on the outside of the unit. I changed the internal air filter last week. There is an ice/freezing rain storm outside. I have turned the unit off to stop it from damaging itself.

I'd like to turn it back on so I get some heat.

If the fan blade is hitting ice on the unit it is better to leave it off and use emergency heat switch on the thermostat until the ice is gone. This will prevent damage to the fan blades.