If the plane is becoming unresponsive and just dropping to the ground, you're stalling it because you're getting it too slow. When doing a landing approach, your primary controls are the throttle and rudder. All the ailerons are really for is to keep the wings level and the elevator maintains a flat attitude. If you feel the nose start to drop while you're approaching, your instinct is to pull back on the elevator. All that does is put the nose up which slows the plane down more, making the stall worse. Use your throttle to control the descent rate and the rudder to steer the plane and you'll be sticking them in no time. I also actually find landing to be easier in a little wind, maybe 5 mph on the sim. It gives you a little more control at really slow ground speeds so you can be more precise.