Your rear end is bouncing?? Did you smack a curb and bend a wheel? You may have broke an axle?
Whats this about the steering? Its hard? You may have broke your belt, ps pump or burnt up your rack.
Drifting in the snow can cause a lot of issues. These cars may be on tv rallying across the world but there is 10s of thousands of dollars over and above the standard wrx/sti put into those cars.. They simply arent built for that stuff.