Rituals and schedules are important to any child but when they get out of hand, they can't always be given in to. Like you noticed, he could unconsciously be wetting the bed more to get into bed with mom and dad. The more one gives into a structure of the child's making (which is scary to the child because the adults are supposed to be in charge but aren't!) the worse it will become.

I don't think there's any way to "neatly" fix Mac's problems and make him comfortable again without his becoming more uncomfortable first. But he needs to have the adults set his schedules and adhere to them and not the other way around. A lot of his anxiety could be coming from his being "in charge" and not having adults "stronger" than he is to keep him safe.