My steering wheel wont move!

I drove it about 5 miles down the road, parked it and when i got back into it to go home, my steering wheel would not turn. The car started fine, but when i put it in reverse to start driving it home the battery light came on and the heat went up to the top line. You can still get the steering wheel to move it is just very hard, i didnt want to mess with it anymore until i figured out what was wrong. I have read online everywhere that the steering wheel is just "locked" but i dont believe that is the problem, seems to me that it must be the power steering pump.. I checked my power steering fluid and the levels were perfect.