Just a psa - You can readily find 34G (etc) bras these days, of quality and style. Macy's in-store? Maybe few & not very awesome, but some online stores* carry numerous brands, price points, styles, etc. And Amazon will have a lot of no-names in a range of sizes, etc, as well as some of the better-knowns.
*Just pulled up barenecessities.com and plugged in 34G (aka 34DDDD), and got 350ish bras ($20 - $220, so a range). 32H (rarer to need) returned 97 models of bras. (I got 25 for 28J) (58J only returned 1, but you get tons below that). You get the picture. They say the carry "76 unique bra sizes in bands 28 to 58 and cup sizes AA to O."
On sizing - as a small-ribcaged, full-boobed person, even "professional" fitters used to size me wrong every damn time. Always too big a band, too small a cup. I'd entertain them by trying what they suggested, then they'd go get what I told them I needed. Every single time. It's only in the last few years that I've started seeing press about how that - wearing too big a band/too small a cup - is the biggest mistake women make, and so you just must get professionally fitted. Lol. Hopefully they measure better now.