Why does it feel like a plane stops in mid-air during approach?
Lowering flaps and gear will add significant drag, which causes the plane to decelerate. Your body feels that, but without visual reference to the ground, your brain has no way to know what speed it was traveling before or after that deceleration.
This is an example of “spatial disorientation”, where the brain gets confusing inputs and comes to the wrong conclusion about what is actually happening. Pilots have instruments to tell us what is actually happening, which we are trained to trust over the suspect data our bodies are giving us, but passengers don’t have that advantage.