If anything, wearing bras constantly would cause your breasts to sag more. It causes the muscles which hold up the breast to weaken, or so one French study states.

It seems you are aware of her manipulation tactics, which of course means you can work on getting away from her. It is much easier for a cult-member who realizes the man preaching salvation-via-mass-suicide is insane to escape than the cult-member who's still completely blinded by his sugary doctrine. My point is you at least have some control-that being of your own mind.
This was all written with the intention of encouragement and/or similar compassion-like emotions, but I'm really not very good with that.