Steering failure

I discover that my steering was not controlling the car direction, the steering was just free rolling on its own and the car would continue in the direction before the failure of the steering and as I struggle with it. I will just discover that it had hook up again and the car would be under control of the steering whenever I enter ditches or potholes or a gallop there is steering control failure and when I enter into another ditch or gallop it will hook back and will gain control. What is wrong with my steering? This has happened to me thrice, and I am afraid to travel with it.