2001 Toyota Corolla Ran over a boulder

Damaged half shaft is very unlikely. If that jerking makes the steering wheel oscillate left and right as the tire rotates, a bent wheel is a good suspect. If the car simply pulls to the right when you let go of the steering wheel, a part got bent or something else happened that caused the alignment to change. Related to that, you'll also usually see the steering wheel is off-center now when driving straight. For the bent part, the lower control arm is the most common cause.

None of those things are terribly serious or expensive but we don't get involved with costs here because there's way too many variables. We don't even know for sure what's wrong yet. The steering and suspension systems should be inspected at a tire and alignment shop. They'll be able to give you an estimate and explain what needs to be done.