You must remove the concrete floor in the shower area up to the line to the left of the wall hung toilet. Pour a new floor in the area 4" lower than the existing floor. Pitch the new concrete towards the drain. Install a typical vinyl shower pan over the concrete as you would for a standard mud-pan shower. Make sure the drain assembly is 2" lower than the existing floor hieght. Fill in the pan with cement as you would for a typical mud-pan shower, tapering the floor to the drain. Install the tile on the whole floor. See attached sketch.
Q
floors choice
Q