I wear underwire most of the time but have a couple of all elastic with no hooks for when costo flairs. Can’t stand the underwire then. Worth it.

Yes I do have rib pain, knots under skin and Costochondritis too. I sure can sympathize with you. The Costochondritis and the rib pain is very painful.

My costocontritis can even go round my back. Try getting a soft crop top type bra and wearing that instead for a bit.

My ribs have been bothering me for years now. The worst area is under my arms and going towards my spine. Wearing a bra is torture for me.

Rib pain 24/7 mostly lower right but can move back, lower left. Just the way you describe :(
Nothing helps, no meds. Had every test, imaging nothing was found. Carrying heavy bags, wrong move, sitting to long may increase the pain. Pressing down on the rib or cartilage makes it worse. It really feels like muscle, cartilage, nerves combined. I do have costohondritis at times. This pain is different, steady, stubborn doesn’t get worse or better when taking deep breath. My costohondritis pain is mostly on left, super sharp or cramp like for seconds , may last on and off for hours or days but gets better.
You can google skipping rib syndrome just in case.
I am planning to ask doctor about nerve block injection.