Reconstruction now too small

I have put on quite a lot of weight since my surgery 12 yrs ago. The natural breast is now a third bigger than the reconstruction. I have been trying to lose weight but it’s not really making any difference to the size of the natural breast. Has anyone had surgery/reverted to mastectomy bra ? The recon just floats around in a bra big enough for the natural one. It’s very obvious that one is bigger than the other and at time of the month is even worse. My clothes are pulled down to one side including my work uniform, causing it to gape open. I’m not one to be too bothered by appearances but it’s just to big a difference in size now.