Help with fit in new unlined underwire with lots of stretch

Hi there, hoping for some help with fit after recent (intentional) weight loss. New measurements are:

Loose 35" Snug 34" Tight 33" Standing 41" Leaning 42" Lying 42"

Calculator gives me 34g, with recommendation to sister size to 36DDD

I had a new bra on order before this so had bought a 36DD. It has lots of stretch.

Using the tightest hook on initial trying on to get band support, so I think I need a 34 in this one; but I am getting some slight spillage over the cups. It feels good in the armpit area etc and everywhere else.

Breastfed two kids and definitely quite pendulous/not self supporting

Just wondering if I should try it in a 34DDD or 34G? Or am I really off base?