I am curious how you think a planet could suddenly stop in its orbit and go the other way.
No, planets don't actually move backwards - its simply how they appear from our point of view as we all orbit the sun at different speeds.
Think of a racetrack. We are one car on the track, along with 7 others. 2 of them move faster than we do, the rest move slower. We all go around the track counterclockwise.
Now imagine its night and all we see is one headlight on each car.
Lets just imagine us and one that is slower than us for a moment.
As we pull ahead and start to curve to the left, the other one seems to move to the left. Then when we get to the exact opposite of the track it seems to stop moving. Then as we start to catch up from behind it seems to be moving to the right.