I am in no way against people getting reductions, but you are just making matters worse by wearing 2-3 improperly fitted bras at the same time.
I have been there. Falling out the top, floppping out the bottom, crazy neck pain, shoulder pain, etc. It was greatly reduced by wearing a single bra that fits. For the first time in my life I could sit with my shoulders back on a horse, and suddenly I stopped having so many refusals on jumping courses.
There are great options out there that are not medieval torture devices like the Enell or minimizers. Smashing your breast tissue down is NOT the solution. My sports bra is a 32H, so I know that they do exist.