Are you asking what WILD is like?

If sleeping on your back is so uncomfortable, then don't. Yeah it's generally agreed that sleeping on your back is the best position (for WILD specifically), but that doesn't mean you can't find another position that's equally as effective. For instance, I recently had two LDs in one night and when I woke up I was curled up on my side. So it's definitely possible, don't be discouraged.