Breast/Chest pain?

I have had pain in my left breast near my sternum for more than 8-10 months at this point since I’ve had my daughter. Probably a year. I’ve been checked by my gyno, all clear. Even requested an ultrasound to be safe and that was clear besides showing some inflammation where my ribs meet my sternum in that area of pain. Still wasn’t satisfied so I went to my family doctor and had an exam too. She said she noticed a slight curve of my spine and was thinking that could cause Costochondritis and the pain. Anyone had this before? I was terrified it would be breast cancer or something (I have health anxiety terribly)