Hi ZoneWolf
First, from the measurement you posted (assuming they are in cm) you should be a full 34B if I am not wrong. (86cm is 33.9 inches, and every 2 inches of extra bust size it's one cup, so your extra 12 cm are 4.7 inches which is a full B). That should be a 12B leaning on 12C AU sizing.
The diet part: all of these "soy, flaxseed, nuts, cruciferous" are fairly weak estrogens. It doesn't hurt to eat them but they alone won't help much with breast growth. Spearmint tea and Zinc are also weak AAs (if any at all). White peony, on the contrary, seems to be a good way to lower T and raise E, because it encourages aromatase, which turns some T into E.
Progesterone helps rounding the shape of breasts but it may slow down growth, so it's advisable that you use it after you have reached a size you already are happy with.
Massage and pumping do help a lot, on the long term.
If you are really committed to growing breasts with herbs, I would suggest you look into getting some Pueraria Mirifica, which is one of the strongest phytoestrogens out there. (Get the pure root powder, no extracts or pills mixed with other stuff).
Good luck and keep us posted!