TMI...Red/Itchy Between Boobs! Help!

This is so embarrassing, I've never had anything like this before getting pregnant. My boobs have grown A TON. Over the past few weeks I started getting a red mark between my boobs and only under the left boob for some reason. It has really begun to itch and now I am worried because there is white stuff there...looks like peeling skin 😔 Has anyone else had this happen to them? I am definitely talking to my doctor next week and may even call sooner.