2004 Dodge Stratus Help-REAR Driver Side Suspension

Hello, I received a blow out today and the way the tire was cut and the way the donut fits on the rear driver side it seems something more than just a tire change is needed. I take it in to get a replacement tire and was told that the rear driverside control arm was split or cracked and so it didn't make sense to place a new tire on because it would cut into the new tire. Is there a such thing as a Driver side rear wheel control arm? What part could/would I need to get to repair this problem? Whats a ball park amount it will cost? Do I need to NOT drive the car until its fixed? It sounds like its rubbing on my donut spare tire.