1999 ford taurus gear box/power steering messed up?

I started my car up and suddenly the power steering locked on me. The gears wouldn't change. I have power steering fluid in the car and the pump works fine. I had someone check it out and they said whenever I shift gears my engine rocks with it and it slips out of place somehow. Is it worth fixing/how much would it cost or should i just sell it?

The price of repairs will exceed the value of the car.

First you say the gears won't change, then you say you can sift the gears and the engine rocks. Rephrase your question. Is it the power steering that's locked up or the gear shifter?