This is assuming you are using 2x6. If you are using 2X4 the 5-1/2 measurment would be 3-1/2. You can also turn the second stud on the left wall 90 degrees so that it forms an L with the first one and still creates drywall backing. This will allow you to insulate more easily. Hope that makes sense.
edit: The spacing on the third stud in on the left wall is actually in the wrong spot. The studs should sit so that any 16" incriment will land directly in the center of a stud. In this diagram it would land on the edge of the stud. I will try to find or make a better diagram, but this might get you going in the right direction.