swollen and tender breasts at 37

Hi I'm a 37 year old mother of two children which are adults now. For several months my breasts have become swollen and tender. Prior to then my breast were quite empty looking and now they look as if I've never really had empty looking breasts. I've spoken to a ob/gyn and i am not premenopausal. They hurt to sleep on and when I get out of bed. Someone please help.