Spatts -- something firstly tells me your mind's eye may not be correct...while for a bb competitor 18% may not be a contest weight, 18% is lean.
And, if the scale is not budging, are you sure you have not put on additional muscle? Since you do look leaner and do not feel spongey could this be it?
Further, perhaps your cutting diet needs more overall cals? Are you getting enough EFAs? I have done carb-depletion several times in my life as well as rotations, but after a while what used to work no longer does. The body adapts too well....we are engineered to stay alive and our bodies will fight claw and tooth to stay there.
Even though you are on a time constraint, have you thought about adding cals? Or an overall cheat day/refeed?
By way of analogy but certainly not to your degree and need of making wieght class.....after months of hard training and super clean eating the scale was NOT moving anywhere. I was at my wits end and ready to throw in the towel. I was deprived and angry. Pissed off to be more accurate. I hated food in general as it lost its luster and appeal and was not eating for pleasure only making myself eat to stay alive and retain muscle.
Well, we needed to move into our new home (actually old home) that needed A TON OF WORK.....tons. My apartment and my then fiance's needed packing. So, diet and training were NOT of a priority. While we did not miss a workout, my diet was crappy. Hot days, lots of boxes, climbing up ladders to fix things.....lots of ice cream, milkshakes, quick foods such as bagels as there were no appliances hooked up etc. YOU GET THE PICTURE.
Well needless to say, I dropped like 7 pounds in a week, did not lose strength, fit into clothes I had not fit into in months and felt re-inspired. Long story to say, you need to take a diet break.