That is great, Robby. You have more courage than I ever did.
I have never been measured professionally. Like you, my research gave all sorts of wrong answers. Each company seems to have its own way of measuring and I tried them all and they were still wrong. There is no way that I am a D or E cup. (40/46) I fill a B and almost a C depending on the style of bra.
You are correct that the issue is the torso size. We tend to have larger band sizes but smaller cup sizes. That somehow doesn't occur to bra manufacturers. I wear a 40 band size comfortably, but to get the cup to fit, I drop down to a 38 B or C. If the band is too tight, I will add an extender to make it comfortable.
I hope yours fits when it arrives. If not, at least you have a starting point to experiment with.