First, what is a "real" force. Real forces are interactions between two objects. Some examples are friction, gravity and the normal force (the force between two surfaces pushing on each other).

There are four forces acting on this block: downward gravitational force, the force from the push, a frictional force, and a normal force from the wall. As a force diagram, it would look like this.

At this point, your body feels “lighter” because the force of gravity and the normal force, of your seat, are working in opposite directions.