Ball shrinking leads to discomfort and problems; unable to stay locked for extended times... seeking assistance.

Hi there, I’m looking for genuine advice. My testicles shrink up to a point where the pain is severe enough that I can’t keep my device on for more than about 12 hours. Currently, I own a newer model of Holy Trainer. When my scrotum is loose and they haven’t pulled back in, it fits well and allows me to wear it comfortably. However, most days, I notice them retracting and shrinking suddenly. This creates growing pain because there’s nowhere for them to go, becoming so agonizing that removal becomes necessary. It happens almost daily now, stopping me from staying locked for extended stretches. Although this seems normal and part of how testicles work, it keeps me from keeping my promise to stay locked for my master, with the goal of eventually having a permanent key holder.