Skin issues

Ka

So when I got pregnant, I went from a C cup to a DDD. For a couple months now, ive had this rash between my breasts that follows where my bra rests, including a line going along the underboob of both breasts. The rash on my underboobs has bumps, and the one right between them isnt raised, but is red and itchy (looks like red splotches). Is there any way that I can help get rid of this? It's driving me insane! Also, at night I have to sleep shirtless because my back and arms itch alot (i never had this issue before pregnancy). My skin problems are gonna drive me insane. Will post pics if needed!