I'm so GLAD you were able to take this step. Even after losing 100 pounds, I'm wearing the same 50DDD bras [having trouble finding bras to get the opportunity to try new size, and FORGET ABOUT finding SPORTS BRAS] and unfortunately the only big difference is having lost the weight in the CHEST area. Now the actual boobage is more ackward than ever since at this rate they will literally soon be at my waist. I took the straps up on one of the bras to hike the girls up, but the weight just pulls the back of the bra up my back, they're higher, but watch out when those puppies are unfurled.. When I gain weight, one of the first places I gain is my chest and also the LAST place I lose. I've had back aches all my life even BEFORE I fell down the 13 steps in '88.
Definitely be sure to wear a bra as long as the doc tells you necessary though. I had a lumpectomy in my left breast a couple years ago [thankfully benign] and the doc told me to be sure to wear a bra 24/7 for I believe it was 6 weeks. OMG when the bra came off [this was before the weight loss so you can image how heavy they were] PAIN!!! I could hardly wait to get the bra BACK ON.. I HATE bras otherwise.
Good luck on your recovery and enjoy your new smaller breasts when they heal.