Chest pain from increased activity

Over the past couple weeks I've noticed a pain in my chest between my cleavage where my sternum is. It's not really muscular because I can't feel any tenderness there, and it feels deep inside like it's my sternum specifically. I do notice muscle tenderness higher up on my pectorals from my boob weight when I run, as this has always been a thing for me. This is new though and it's pretty annoying and painful. I've always mitigated the muscular strain from good sports bras but now I can't even run, let alone breathe deeply without the middle of my chest hurting and I'm curious if anyone else has experienced/mitigated this somehow?

Also I'm meeting with my PCM next week to start the process for looking into a reduction because I'm sick of this shit.