Can't find a good shapewear option for a low backed strapless wedding dress

I found a wedding dress I love- it's corseted and sleeveless, with a lower back and a beaded drop waist bodice. It's made with a satin material. The only issue- I'm plus size, and the way the corset fits makes my back look like an overfilled muffin. I need some kind of shapewear that has a low back and is strapless, but will still provide some side and front support for the girls, while also forcing my back fat to behave by either holding it down or holding it forward. Does anyone have any suggestions? I have my second fitting in a month so I have a little time to find it