Don't feel bad, that happened to me twice. I just recently went from a 36DD to a freaking 32G, and I was like, how did I not figure this out after the first fitting?

You know the 'down a band size, up a cup-size, reverse' thing, right? It's how you fiddle up and down to see what works best in a brand. If you got up one, go down the other at least one step.