Burning in Nipples.

I woke up the other morning and I had a burning in my right nipple. Now a red rash area as formed next to the areola. Also under the red rash is a hard knot. The knot has started buldging a little. The pain is so bad it hurts for me to wear a bra b/c it touches it but if im not wearing a bra it hurts for me to move b/c any movement from my breast hurts it worse. Someone please tell me what this could be.