Undergarments/shapewear?

My gown! My gown to be in soon!!!

I'm assuming your gown is strapless since you mentioned having a strapless bra from Soma (side note on Soma if you hate the bra it's likely because it isn't a proper fit... Might want to have a fitting with Soma again). If your gown is strapless, you have a couple options. You can either have your seamstress add some nice straps just wide enough to cover a flesh-toned bra strap. Or if you are set on a strapless dress, make sure that your dress has boning (think corset). Having boning in the bodice of your dress will give you support for your "assets" and will have a minimizing effect on other aspects of your shape. If your seamstress is a good one, it'll be nothing for them to add boning or reinforce the flimsy plastic strips that are already in the dress. Honestly, you might want to ensure the dress has boning regardless of whether it has straps or not...
Congrats on your wedding and best of luck in your search for comfortable shape wear!

I have a Low back corset from Nordstrom to hold up the girls and smooth the stomach and then I have a pair of spanx shorts to help with the bottom part of my midsection and to avoid the chub rub. It smooths me perfectly

Spanx just came out with low back shapewear! I just ordered one over the weekend and hoping it does the trick!

I am a busty gal! I am wearing a mermaid/fit and flair so I had the same worries. I went into a lingerie specialty store. They fit you and generally carry a wider more quality range of sizes of all lingerie. I got professionally fitted a few years back and swear by it! Anyhoo I ended up being fit for a beautiful corset which lifts and holds the girls in place but also slims my tummy. We tried adding shapewear but it seemed worse with it if you can believe that. I’m going to find a high rise brief before my first fitting but that’s it. If your dress has some structure to the bodice you might end up in the same boat. But definitely try a specialty store. It is such a good experience and you’ll have better selection. I’m in Virginia and love Trousseau but it will be location dependent I’m sure.

I'm very busy as well. (32K) so I feel your pain. For mine I just didnt wear a bra. I had my seamstress add cups and make my dress tight enough that I didnt feel like London bridge was fall down. I will say there are a few photos where there is more cleavage than I would have liked, but all in all I'm very happy with how that worked out. If you have a corseted back this should not be a problem at all. Some boning in the front for support and a well tied corset, no bra necessary.